g3408 and g3412 engines maintenance intervals

®© 2010 CaterpillarAll Rights Reserved

®

MAINTENANCE INTERVALSOperation and Maintenance Manual Excerpt

SEBU6682-08May 2006

Operation andMaintenanceManualG3408 and G3412 Engines6NB1-Up (Engine)7DB1-Up (Engine)6RJ1-Up (Engine)3NK1-Up (Engine)

SEBU6682-08 69Maintenance Section

Maintenance Interval Schedule

i02522249

Maintenance Interval Schedule(Turbocharged AftercooledEngines)SMCS Code: 1000; 4450; 7500

Ensure that all safety information, warnings andinstructions are read and understood before anyoperation or any maintenance procedures areperformed.

The user is responsible for the performance ofmaintenance, including all adjustments, the use ofproper lubricants, fluids, filters, and the replacementof components due to normal wear and aging. Failureto adhere to proper maintenance intervals andprocedures may result in diminished performance ofthe product and/or accelerated wear of components.

Use mileage, fuel consumption, service hours, orcalendar time, WHICHEVER OCCURS FIRST,in order to determine the maintenance intervals.Products that operate in severe operating conditionsmay require more frequent maintenance.

Note: Before each consecutive interval is performed,all maintenance from the previous interval must beperformed.

When Required

Batteries - Replace ............................................... 77Engine Air Cleaner Element - Replace ................. 91Overhaul Considerations .................................... 121Valve Stem Projection - Measure/Record ........... 127

Daily

Air Starting Motor Lubricator Oil Level - Check .... 75Air Tank Moisture and Sediment - Drain ............... 76Control Panel - Inspect ......................................... 83Cooling System Coolant Level - Check ................ 86Driven Equipment - Inspect/Replace/Lubricate ... 91Engine Air Cleaner Service Indicator - Inspect ..... 93Engine Air Precleaner - Clean .............................. 94Engine Oil Level - Check ...................................... 97Fuel System Fuel Filter Differential Pressure -Check ................................................................ 103Instrument Panel - Inspect ................................... 113Walk-Around Inspection ...................................... 129

Every 250 Service Hours

Engine Oil Sample - Obtain .................................. 98


Aftercooler Core - Clean/Test ............................... 74Battery Electrolyte Level - Check .......................... 78

Belts - Inspect/Adjust/Replace .............................. 82Cooling System Coolant Sample (Level 1) -Obtain ................................................................. 86Cooling System Supplemental Coolant Additive(SCA) - Test/Add ................................................. 87Crankshaft Vibration Damper - Inspect ................. 89Engine - Clean ...................................................... 91Engine Oil and Filter - Change ............................. 99Engine Valve Lash - Inspect/Adjust .................... 101Engine Valve Rotators - Inspect ......................... 102Exhaust Piping - Inspect ..................................... 103Gas Pressure Regulator - Check ........................ 103Hoses and Clamps - Replace ............................. 107Ignition System Spark Plugs - Check/Adjust/Replace ............................................................. 108Ignition System Timing - Check/Adjust ................ 113Inlet Air System - Inspect ..................................... 113Radiator - Clean .................................................. 123

Initial 750 Service Hours

Valve Stem Projection - Measure/Record ........... 127


Actuator Control Linkage - Lubricate .................... 74Carburetor Air/Fuel Ratio - Check/Adjust ............. 83Crankcase Blowby - Measure/Record .................. 88Cylinder Pressure - Measure/Record ................... 89Engine Crankcase Breather - Clean ..................... 95Engine Oil Filter (Auxiliary) - Change ................... 96Engine Protective Devices - Check .................... 101Engine Speed/Timing Sensor - Clean/Inspect .... 101Speed Sensor - Clean/Inspect ............................ 123


Air Starting Motor Lubricator Bowl - Clean ........... 75Cooling System Coolant Sample (Level 2) -Obtain ................................................................. 87Driven Equipment - Check .................................... 90Engine Mounts - Check ........................................ 95Ignition System Transformer Resistance - Test ... 113Inlet Air System - Inspect ..................................... 113Starting Motor - Inspect ...................................... 125Water Pump - Inspect ......................................... 131


Alternator - Inspect ............................................... 76


Turbocharger - Inspect ........................................ 126

Between 9000 and 12 000 Service Hours

Overhaul (Top End) .............................................. 119

Between 18 000 and 24 000 Service Hours

Overhaul (Major) .................................................. 117

70 SEBU6682-08Maintenance SectionMaintenance Interval Schedule

Every 24 000 Service Hours or 3 Years

Cooling System Coolant (NGEC) - Change .......... 84



i02522248

Maintenance Interval Schedule(Naturally Aspirated Engines)SMCS Code: 1000; 4450; 7500





When Required

Batteries - Replace ............................................... 77Engine Air Cleaner Element - Replace ................. 91Overhaul Considerations .................................... 121Valve Stem Projection - Measure/Record ........... 127

Daily

Air Starting Motor Lubricator Oil Level - Check .... 75Air Tank Moisture and Sediment - Drain ............... 76Control Panel - Inspect ......................................... 83Cooling System Coolant Level - Check ................ 86Driven Equipment - Inspect/Replace/Lubricate ... 91Engine Air Cleaner Service Indicator - Inspect ..... 93Engine Air Precleaner - Clean .............................. 94Engine Oil Level - Check ...................................... 97Fuel System Fuel Filter Differential Pressure -Check ................................................................ 103Instrument Panel - Inspect ................................... 113Walk-Around Inspection ...................................... 129


Engine Oil Sample - Obtain .................................. 98


Battery Electrolyte Level - Check .......................... 78Belts - Inspect/Adjust/Replace .............................. 82Cooling System Coolant Sample (Level 1) -Obtain ................................................................. 86

Cooling System Supplemental Coolant Additive(SCA) - Test/Add ................................................. 87Crankshaft Vibration Damper - Inspect ................. 89Engine - Clean ...................................................... 91Engine Oil and Filter - Change ............................. 99Exhaust Piping - Inspect ..................................... 103Hoses and Clamps - Replace ............................. 107Ignition System Spark Plugs - Check/Adjust/Replace ............................................................. 108Ignition System Timing - Check/Adjust ................ 113Inlet Air System - Inspect ..................................... 113Radiator - Clean .................................................. 123

Initial 750 Service Hours

Engine Valve Lash - Inspect/Adjust .................... 101Engine Valve Rotators - Inspect ......................... 102Gas Pressure Regulator - Check ........................ 103Valve Stem Projection - Measure/Record ........... 127


Actuator Control Linkage - Lubricate .................... 74Carburetor Air/Fuel Ratio - Check/Adjust ............. 83Crankcase Blowby - Measure/Record .................. 88Cylinder Pressure - Measure/Record ................... 89Engine Crankcase Breather - Clean ..................... 95Engine Oil Filter (Auxiliary) - Change ................... 96Engine Protective Devices - Check .................... 101Engine Speed/Timing Sensor - Clean/Inspect .... 101Engine Valve Lash - Inspect/Adjust .................... 101Engine Valve Rotators - Inspect ......................... 102Gas Pressure Regulator - Check ........................ 103Speed Sensor - Clean/Inspect ............................ 123


Air Starting Motor Lubricator Bowl - Clean ........... 75Cooling System Coolant Sample (Level 2) -Obtain ................................................................. 87Driven Equipment - Check .................................... 90Engine Mounts - Check ........................................ 95Ignition System Transformer Resistance - Test ... 113Inlet Air System - Inspect ..................................... 113Starting Motor - Inspect ...................................... 125Water Pump - Inspect ......................................... 131


Alternator - Inspect ............................................... 76


Overhaul (Top End) .............................................. 119


Overhaul (Major) .................................................. 117

Every 24 000 Service Hours or 3 Years

Cooling System Coolant (NGEC) - Change .......... 84

72 SEBU6682-08Maintenance SectionMaintenance Interval Schedule

i02522245

Maintenance Interval Schedule(Standby Generator SetEngines)SMCS Code: 1000; 4450; 7500





When Required

Generator - Dry ................................................... 104Generator Set - Test ........................................... 106Varistor - Test ...................................................... 129Winding - Test ..................................................... 132

Daily

Generator Load - Check ..................................... 105Power Factor - Check ......................................... 122Stator Winding Temperature - Measure/Record .. 126

Every Week

Air Starting Motor Lubricator Oil Level - Check .... 75Air Tank Moisture and Sediment - Drain ............... 76Automatic Start/Stop - Inspect .............................. 76Battery Charger - Check ....................................... 77Battery Electrolyte Level - Check .......................... 78Bearing Temperature - Measure/Record .............. 82Control Panel - Inspect ......................................... 83Cooling System Coolant Level - Check ................ 86Engine Air Cleaner Service Indicator - Inspect ..... 93Engine Air Precleaner - Clean .............................. 94Engine Oil Level - Check ...................................... 97Fuel System Fuel Filter Differential Pressure -Check ................................................................ 103Instrument Panel - Inspect ................................... 113Jacket Water Heater - Check ............................... 117

Space Heater - Check ........................................ 123Standby Generator Set MaintenanceRecommendations ............................................ 124Walk-Around Inspection ...................................... 130

Every 250 Service Hours or 1 Year

Engine Oil and Filter - Change ............................. 99

Every 6 Months

Stator Lead - Check ............................................ 125

Every Year

Actuator Control Linkage - Lubricate .................... 74Aftercooler Core - Clean/Test ............................... 74Air Starting Motor Lubricator Bowl - Clean ........... 75Alternator - Inspect ............................................... 76Bearing (Ball) - Lubricate ...................................... 78Belts - Inspect/Adjust/Replace .............................. 82Carburetor Air/Fuel Ratio - Check/Adjust ............. 83Cooling System Coolant Sample (Level 1) -Obtain ................................................................. 86Cooling System Coolant Sample (Level 2) -Obtain ................................................................. 87Cooling System Supplemental Coolant Additive(SCA) - Test/Add ................................................. 87Crankcase Blowby - Measure/Record .................. 88Crankshaft Vibration Damper - Inspect ................. 89Cylinder Pressure - Measure/Record ................... 89Engine - Clean ...................................................... 91Engine Air Cleaner Element - Replace ................. 91Engine Crankcase Breather - Clean ..................... 95Engine Mounts - Check ........................................ 95Engine Oil Sample - Obtain .................................. 98Engine Performance - Test ................................. 101Engine Protective Devices - Check .................... 101Engine Speed/Timing Sensor - Clean/Inspect .... 101Engine Valve Lash - Inspect/Adjust .................... 101Engine Valve Rotators - Inspect ......................... 102Gas Pressure Regulator - Check ........................ 103Generator Set Vibration - Inspect ....................... 107Ignition System Spark Plugs - Check/Adjust/Replace ............................................................. 108Ignition System Timing - Check/Adjust ................ 113Inlet Air System - Inspect ..................................... 113Insulation - Test .................................................... 114Radiator - Clean .................................................. 123Speed Sensor - Clean/Inspect ............................ 123Starting Motor - Inspect ...................................... 125Turbocharger - Inspect ........................................ 126Water Pump - Inspect ......................................... 131

Every 3 Years

Batteries - Replace ............................................... 77Cooling System Coolant (NGEC) - Change .......... 84Exhaust Bypass - Inspect ................................... 102Exhaust Piping - Inspect ..................................... 103Governor - Inspect .............................................. 107Hoses and Clamps - Replace ............................. 107



Ignition System Spark Plug Wires - Replace ...... 107Ignition System Transformer Resistance - Test ... 113Water Temperature Regulator - Replace ............ 131

Overhaul

Bearing - Inspect ................................................... 79

74 SEBU6682-08Maintenance SectionActuator Control Linkage - Lubricate

i01616158

Actuator Control Linkage -LubricateSMCS Code: 1265-086

g00836634Illustration 58Grease fitting on the linkage for the governor control lever

g00836635Illustration 59Grease fitting on the linkage for the throttle control

Lubricate the grease fittings with MPGM.

Check the LinkageCheck the linkage for proper operation. Adjust thelinkage, if necessary. For instructions on adjustmentof the linkage, refer to the engine’s Specifications.

i01371758

Aftercooler Core - Clean/Test(Air-To-Air Aftercooler)SMCS Code: 1064-070; 1064-081; 1064

Note: Adjust the frequency of cleaning according tothe effects of the operating environment.

Inspect the aftercooler for these items: damaged fins,corrosion, dirt, grease, insects, leaves, oil, and otherdebris. Clean the aftercooler, if necessary.

For air-to-air aftercoolers, use the same methods thatare used for cleaning radiators.

Personal injury can result from air pressure.

Personal injury can result without following prop-er procedure.When using pressure air, wear a pro-tective face shield and protective clothing.

Maximum air pressure at the nozzle must be lessthan 205 kPa (30 psi) for cleaning purposes.

Pressurized air is the preferred method for removingloose debris. Direct the air in the opposite directionof the fan’s air flow. Hold the nozzle approximately6 mm (0.25 inch) away from the fins. Slowly move theair nozzle in a direction that is parallel with the tubes.This will remove debris that is between the tubes.

Pressurized water may also be used for cleaning.The maximum water pressure for cleaning purposesmust be less than 275 kPa (40 psi). Use pressurizedwater in order to soften mud. Clean the core fromboth sides.

Use a degreaser and steam for removal of oil andgrease. Clean both sides of the core. Wash the corewith detergent and hot water. Thoroughly rinse thecore with clean water.

After cleaning, start the engine and accelerate theengine to high idle rpm. This will help in the removalof debris and drying of the core. Stop the engine.Use a light bulb behind the core in order to inspectthe core for cleanliness. Repeat the cleaning, ifnecessary.

Inspect the fins for damage. Bent fins may be openedwith a “comb”.

Note: If parts of the aftercooler system are repairedor replaced, a leak test is highly recommended.

Inspect these items for good condition: welds,mounting brackets, air lines, connections, clamps,and seals. Make repairs, if necessary.

For more detailed information on cleaning andinspection, see Special Publication, SEBD0518,“Know Your Cooling System”.


Air Starting Motor Lubricator Bowl - Clean

i02344769

Air Starting Motor LubricatorBowl - CleanSMCS Code: 1451-070

If the engine is equipped with an air starting motor,use the following procedure:

Personal injury can result from removing hoses orfittings in a pressure system.

Failure to relieve pressure can cause personal in-jury.

Do not disconnect or remove hoses or fittings un-til all pressure in the system has been relieved.

1. Ensure that the air supply to the lubricator is OFF.

g00745554Illustration 60(1) Filler plug(2) Bowl(3) Drain valve

2. Slowly loosen filler plug (1) in order to release thepressure from the lubricator.

NOTICECare must be taken to ensure that fluids are containedduring performance of inspection, maintenance, test-ing, adjusting and repair of the product. Be prepared tocollect the fluid with suitable containers before open-ing any compartment or disassembling any compo-nent containing fluids.

Refer to Special Publication, NENG2500, “CaterpillarDealer Service Tool Catalog” for tools and suppliessuitable to collect and contain fluids on Caterpillarproducts.

Dispose of all fluids according to local regulations andmandates.

3. Place a suitable container under bowl (2) andopen drain valve (3) in order to drain the oil fromthe bowl.

4. Remove bowl (2). Clean the bowl with warm water.

5. Dry the bowl. Inspect the bowl for cracks. If thebowl is cracked, replace the damaged bowl witha new bowl. Inspect the gasket. If the gasket isdamaged, replace the gasket.

6. Install the bowl.

7. Make sure that drain valve (3) is closed.

8. For instructions on filling the lubricator, see thisOperation and Maintenance Manual, “Air StartingMotor Lubricator Oil Level - Check” topic.

i02213914

Air Starting Motor LubricatorOil Level - CheckSMCS Code: 1451-535

NOTICENever allow the lubricator bowl to become empty. Theair starting motor will be damaged by a lack of lubrica-tion. Ensure that sufficient oil is in the lubricator bowl.

g00745561Illustration 61

1. Observe the oil level in sight gauge (3). If the oillevel is less than 1/2, add oil to the lubricator bowl.

76 SEBU6682-08Maintenance SectionAir Tank Moisture and Sediment - Drain

Personal injury can result from removing hoses orfittings in a pressure system.

Failure to relieve pressure can cause personal in-jury.

Do not disconnect or remove hoses or fittings un-til all pressure in the system has been relieved.

2. Ensure that the air supply to the lubricator is OFF.Slowly loosen filler plug (4) in order to releasepressure from the lubricator bowl.

3. Remove filler plug (4). Pour oil into the lubricatorbowl. Use nondetergent SAE 10W oil fortemperatures that are greater than 0 °C (32 °F).Use air tool oil for temperatures that are below0 °C (32 °F).

4. Install filler plug (4).

Adjust the LubricatorNote: Adjust the lubricator with a constant rate of airflow. After the adjustment, the lubricator will releaseoil in proportion to variations of the air flow.

1. Ensure that the fuel supply to the engine is OFF.

NOTICEDo not crank the engine continuously for more than30 seconds. Allow the starting motor to cool for twominutes before cranking the engine again.

2. Operate the air starting motor. Observe the dropsof oil that are released in dome (1).

Note: Some lubricators have an adjustment screwrather than a knob.

3. If necessary, adjust the lubricator in orderto release from one to three drops of oil persecond. To increase the rate, turn knob (2)counterclockwise. To decrease the rate, turn theknob clockwise.

i00351324

Air Tank Moisture andSediment - DrainSMCS Code: 1466-543-M&S

Moisture and sediment in the air starting system cancause the following conditions:

• Freezing

• Corrosion of internal parts

• Malfunction of the air starting system

When opening the drain valve, wear protectivegloves, a protective face shield, protective cloth-ing, and protective shoes. Pressurized air couldcause debris to be blown and result in personalinjury.

1. Open the drain valve that is on the bottom of theair tank. Allow the moisture and sediment to drain.

2. Close the drain valve.

i02084374

Alternator - InspectSMCS Code: 1405-040

Inspect the alternator for the following conditions:

• Proper connections

• Clean ports for cooling airflow

• Proper charging of the battery

Observe the ammeter during engine operation inorder to ensure proper battery performance and/orproper performance of the electrical system.

Make repairs, if necessary. See the Service Manualfor service procedures. Consult your Caterpillardealer for assistance.

i01039675

Automatic Start/Stop - Inspect(Generator Set)SMCS Code: 4462

The generator set must be ready to operate under aload at any time. After performing maintenance onthe generator set, inspect the position of the controlswitches. Ensure the following conditions:

• The starting system is enabled.

• The control switches are in the correct position forautomatic starting.

SEBU6682-08 77Maintenance SectionBatteries - Replace

• The switchgear and the automatic transfer switchesthat are associated with the generator are enabled.

For more information, see the Operation andMaintenance Manual for the generator and thecontrol panel.

i01041029

Batteries - ReplaceSMCS Code: 1401-510

Batteries give off combustible gases which canexplode. A spark can cause the combustible gas-es to ignite. This can result in severe personal in-jury or death.

Ensure proper ventilation for batteries that are inan enclosure. Follow the proper procedures in or-der to help prevent electrical arcs and/or sparksnear batteries. Do not smoke when batteries areserviced.

1. Turn the key start switch to the OFF position.Remove the key and all electrical loads.

2. Turn OFF the battery charger. Disconnect thecharger.

3. The NEGATIVE “-” cable connects the NEGATIVE“-” battery terminal to the ground plane. Disconnectthe cable from the NEGATIVE “-” battery terminal.

4. The POSITIVE “+” cable connects the POSITIVE“+” battery terminal to the starting motor.Disconnect the cable from the POSITIVE “+”battery terminal.

Note: Always recycle a battery. Never discard abattery. Return used batteries to an appropriaterecycling facility.

5. Remove the used battery.

6. Install the new battery.

Note: Before connecting the cables, ensure that thekey start switch is OFF.

7. Connect the cable from the starting motor to thePOSITIVE “+” battery terminal.

8. Connect the cable from the ground plane to theNEGATIVE “-” battery terminal.

i01039758

Battery Charger - CheckSMCS Code: 1401-535

Checking Before Start-UpCheck the battery charger for proper operation. Ifthe batteries are properly charged, the needle of theammeter will register near “0” (zero).

The battery charger must not produce excessivecurrent during start-up. Alternatively, the chargermust be automatically disconnected for start-up.If the engine has an alternator, the charger mustbe automatically disconnected during start-up andduring engine operation.

Charging the Battery

Never disconnect any charging unit circuit or bat-tery circuit cable from the battery when the charg-ing unit is operated. A spark can cause an explo-sion from the flammable vapor mixture of hydro-gen and oxygen that is released from the elec-trolyte through the battery outlets. Injury to per-sonnel can be the result.

Perform the following procedure to charge thebattery:

1. Ensure that the charger is turned OFF.

2. Adjust the voltage of the charger in order to matchthe voltage of the battery.

3. Connect the POSITIVE “+” lead of the chargerto the POSITIVE “+” battery terminal. Connectthe NEGATIVE “-” lead of the charger to theNEGATIVE “-” battery terminal.

4. Turn ON the battery charger.

Overcharging of Batteries

Overcharging reduces the service life of batteries.Use a battery charger that will not overcharge thebattery. DO NOT charge the battery if the meter ofthe battery charger is in the RED zone.

Overcharging is indicated by the following symptoms:

• The battery is very warm to the touch.

• A strong odor of acid is present.

• The battery emits smoke or a dense vapor (gas).

78 SEBU6682-08Maintenance SectionBattery Electrolyte Level - Check

Perform one of the following procedures if the batteryshows symptoms of overcharging:

• Reduce the rate of charging by a significantamount. Complete the charging at the reducedrate.

• Turn OFF the charger.

Table 21 describes the effects of overcharging ondifferent types of batteries.

Table 21

Effects of Overcharging Batteries

Type of Battery Effect

All of the battery cells havea low level of electrolyte.

When the plates of thebattery are inspectedthrough the filler holes, theplates may appear to bewarped. This is caused byan excessive temperature.

Caterpillar General ServiceBatteriesCaterpillar Premium HighOutput Batteries

The battery may not passa load test.

The battery may not accepta charging current.

Caterpillar MaintenanceFree Batteries

The battery may not passa load test.

Checking After StoppingEnsure that the battery charger is connectedproperly. Observe the meter of the charger. Recordthe amperage.

i02340858

Battery Electrolyte Level -CheckSMCS Code: 1401-535-FLV

When the engine is not run for long periods of time orwhen the engine is run for short periods, the batteriesmay not fully recharge. Ensure a full charge in orderto help prevent the battery from freezing. If batteriesare properly charged, ammeter reading should bevery near zero, when the engine is in operation.

All lead-acid batteries contain sulfuric acid whichcan burn the skin and clothing. Always wear a faceshield and protective clothing when working on ornear batteries.

1. Remove the filler caps. Maintain the electrolytelevel to the “FULL” mark on the battery.

If the addition of water is necessary, use distilledwater. If distilled water is not available use cleanwater that is low in minerals. Do not use artificiallysoftened water.

2. Check the condition of the electrolyte with the245-5829 Coolant Battery Tester Refractometer.

3. Keep the batteries clean.

Clean the battery case with one of the followingcleaning solutions:

• A mixture of 0.1 kg (0.2 lb) of baking soda and1 L (1 qt) of clean water

• A mixture of 0.1 L (0.11 qt) of ammonia and 1 L(1 qt) of clean water

Thoroughly rinse the battery case with clean water.

Use a fine grade of sandpaper to clean theterminals and the cable clamps. Clean the itemsuntil the surfaces are bright or shiny. DO NOTremove material excessively. Excessive removalof material can cause the clamps to not fit properly.Coat the clamps and the terminals with 5N-5561Silicone Lubricant, petroleum jelly or MPGM.

i02023749

Bearing (Ball) - Lubricate(Generator)SMCS Code: 4471-086

The following ball bearings must be lubricated:no shield and single shield. Double shielded ballbearings may not require lubrication. Refer to theinstructions that are located on the machine.

For ball bearings, use Caterpillar 2S-3230 BearingLubricant. This grease is an NLGI No. 2 Grade.There is Polyurea (a thickener) in this grease. Thetemperature range of Caterpillar 2S-3230 BearingLubricant is −29 °C (−20.2 °F) to 177 °C (350.6 °F).For extremely low temperatures, use either NLGI No.1 Grade or NLGI No. 0 Grade.


Bearing - Inspect

Lubricating Process1. Remove either the louver assembly or the rearplate from the rear of the generator housing.

2. Remove the top grease pipe plug and remove thelower grease pipe plug.

3. Install a grease fitting in the grease pipe.

4. Grease the shielded ball bearings with 2S-3230Bearing Lubricant (53.28 mL (1.8 ounces) to59.20 mL (2.0 ounces)). Lubricate shielded ballbearings at 2000 hour intervals. Do not mixgreases.

Note: Some two-bearing generators have sphericalroller bearings in the front bracket and ball bearings inthe rear bracket. These units should use a common108-8611 Grease Cartridge. This grease should beused for the front bearing and the rear bearing.

5. Wipe off the excess grease. Remove the topgrease fitting. Install the plug.

6. Operate the generator for one hour. This will allowthe grease to expand. The expanding grease willforce the excess grease from the cavity. Whenthe excess grease is forced from the cavity, theinternal pressure will be reduced. The generatorshould continue to operate until the grease stopspurging.

7. Stop the engine. Install the plug in the bottomgrease pipe. Wipe off the excess grease.

8. Install the louver assembly or install the rear plate.

i02230503

Bearing - InspectSMCS Code: 4471-040

The following maintenance procedure for generatorbearings should be followed at every major engineoverhaul:

1. Remove the bearing bracket. Inspect the followingitems: bracket bore, bearing outer race, androlling elements. On standby power units, thebearing must be inspected and the grease mustbe replaced at three year intervals. The sleevefor the bearing bracket should be inspected forout of roundness, excessive wear, and a bracketstep that is less than 0.0762 mm (0.0030 inch). Ifthere is no sleeve for the bearing bracket, inspectthe bore for the bearing bracket. The bearingshould be inspected for damage to the outer race,severe fretting, and smoothness of operation.When possible, the bearing elements should beinspected. Some double shielded ball bearingsprevent visual inspection of the ball bearings.Other double shielded ball bearings have aretaining ring. This retaining ring can be removedin order to allow access for a visual inspection ofthe ball bearings.

On two-bearing generators, the front bearing canonly be removed after the hub is removed. In orderto remove the hub, cut off the hub. Pulling the hubwill damage the shaft.

Note: Bearings that are being removed for failureanalysis should not be cut off with a torch.

2. Spherical Roller Bearing should be cleaned andrepacked with 108-8611 Grease. Pack thebearing and pack the cavity (one-third to one-halfof the volume of the cavity). The bearing shouldbe filled with 88.8 mL (3 ounces) to 118.4 mL(4 ounces) of grease. The cavity should be filledwith 118.4 mL (4 ounces) to 148.0 mL (5 ounces)of grease. Refer to Table 22.

3. All ball bearings should be cleaned. The cavity ofthe bracket should be repacked with 2S-3230Grease. Pack the bearings (one-third to one-halfof the volume of the cavity). Refer to Table 22.

To reinstall bearings, heat the bearings to 107 °C(224.6 °F) for ten minutes. Mount the bearingson the shaft. To reinstall the hub, heat the hub to400 °C (752.0 °F) for three hours. Mount the hubto the shaft.

4. Ensure that the tube that supplies grease to thebearing is filled with grease.

5. Remove the bracket drain plug and operate thegenerator for one hour. This will allow the greaseto expand. The expanding grease will force theexcess grease from the cavity. When the excessgrease is forced from the cavity, the internalpressure will be reduced. The generator shouldcontinue to operate until the grease stops purging.

6. Stop the engine. Install the bracket drain plug.Wipe off the excess grease.

80 SEBU6682-08Maintenance SectionBearing - Inspect

7. For greasing intervals, follow the recommendationson the lubrication plate (if equipped) or refer toMaintenance Schedule, “Bearing - Lubricate”.Whenever the bearings are greased, repeat Step5. DO NOT MIX GREASES.

Table 22

BearingOutsideDiametermm (inch)

BearingInsideDiametermm (inch)

PartNumber

GeneratorFrameSize

Bearing Borein Bracketmm (inch)

BearingShield(Type)

BearingCavityGreasemL (oz)

Rotor ShaftDiametermm (inch)

100.000 mm(3.9370 inch)

45.000 mm(1.7717 inch)

5P-1977 All 360 100.000 mm(3.9370 inch)

to100.025 mm(3.9380 inch)

Double 29.6 mL(1 oz)

45.004 mm(1.7718inch)to

45.019 mm(1.7724inch)

140.000 mm(5.5118 inch)

65.000 mm(2.5591 inch)

3N-1965 440(round

laminated)

140.002 mm(5.5119 inch)

to140.028 mm(5.5129 inch)

Double 53.280 mL(1.8 oz)(1)

to94.720 mL(3.2 oz)(2)

65.004 mm(2.5592inch)to

65.021 mm(2.5599inch)

160.000 mm(6.2992 inch)

75.000 mm(2.9527 inch)

5P-2448 580(2)590(1)

160.002 mm(6.2993 inch)

to160.028 mm(6.3003 inch)

Double 100.64 mL(3.4 oz)to

168.72 mL(5.7 oz)

75.004 mm(2.9529inch)to

75.021 mm(2.9536inch)

170.000 mm(6.6929 inch)

80.000 mm(3.1496 inch)

4L-6677(3) 580(1) 170.002 mm(6.6930 inch)

to170.028 mm(6.6940 inch)

Single 97.68 mL(3.3 oz)to

162.80 mL(5.5 oz)

80.002 mm(3.1497inch)to

80.020 mm(3.1504inch)

170.000 mm(6.6929 inch)

80.000 mm(3.1496 inch)

109-7687(3) 580(1) 170.002 mm(6.6930 inch)

to170.028 mm(6.6940 inch)


162.80 mL(5.5 oz)

80.002 mm(3.1497inch)to

80.020 mm(3.1504inch)

180.000 mm(7.0866 inch)

100.000 mm(3.9370 inch)

6Y-3955 440(squarelaminated)

179.992 mm(7.0863 inch)

to180.017 mm(7.0873 inch)


230.88 mL(7.8 oz)

100.012 mm(3.9375inch)to

100.028 mm(3.9381inch)

190.000 mm(7.4803 inch)

90.000 mm(3.5433 inch)

6Y-6488 590(1)589 PM

190.002 mm(7.4804 inch)

to190.028 mm(7.4814 inch)


162.80 mL(5.5 oz)

90.012 mm(3.5438inch)to

90.028 mm(3.5444inch)(continued)


Bearing - Inspect

(Table 22, contd)



PartNumber

GeneratorFrameSize


BearingShield(Type)



225.000 mm(8.8582 inch)

105.000 mm(4.1338 inch)

6V-0410 680(1) 225.003 mm(8.8584 inch)

to225.034 mm(8.8596 inch)


230.88 mL(7.8 oz)

105.029 mm(4.1350inch)to

105.034 mm(4.1352inch)

225.000 mm(8.8582 inch)

105.000 mm(4.1338 inch)

108-1760 680(1) 225.003 mm(8.8584 inch)

to225.034 mm(8.8596 inch)


236.80 mL(8.0 oz)

105.029 mm(4.1350inch)to

105.034 mm(4.1352inch)

230.000 mm(9.0551 inch)

130.000 mm(5.1181 inch)

2L-4444(4) 8084 pole(1)

229.992 mm(9.0548 inch)

to230.022 mm(9.0560 inch)

Open 177.60 mL(6.0 oz)to

266.40 mL(9.0 oz)

130.028 mm(5.1192 inch)

to130.051 mm(5.1201inch)

230.000 mm(9.0551 inch)

130.000 mm(5.1181 inch)

2L-4444(4) 820(1) 229.992 mm(9.0548 inch)

to230.022 mm(9.0560 inch)

Open 236.8 mL(8.0 oz)to

355.20 mL(12.0 oz)

130.028 mm(5.1192 inch)

to130.051 mm(5.1201inch)

240.000 mm(9.4488 inch)

110.000 mm(4.3307 inch)

108-1761 690(1) 240.002 mm(9.4489 inch)

to240.033 mm(9.4501 inch)


296.00 mL(10.0 oz)(2)414.40 mL(14.0 oz)

to621.60 mL(21 oz)(3)

110.012 mm(4.3312inch)to

110.028 mm(4.3318inch)

240.000 mm(9.4488 inch)

110.000 mm(4.3307 inch)

6V-3310 800(1) 240.002 mm(9.4489 inch)

to240.033 mm(9.4501 inch)


239.76 mL(8.1 oz)

110.012 mm(4.3312inch)to

110.028 mm(4.3318inch)

240.000 mm(9.4488 inch)

110.000 mm(4.3307 inch)

6V-6752 800(1) 240.002 mm(9.4489 inch)

to240.033 mm(9.4501 inch)


239.76 mL(8.1 oz)

110.012 mm(4.3312inch)to

110.028 mm(4.3318inch)(continued)

82 SEBU6682-08Maintenance SectionBearing Temperature - Measure/Record

(Table 22, contd)



PartNumber

GeneratorFrameSize


BearingShield(Type)



240.000 mm(9.4488 inch)

110.000 mm(4.3307 inch)

108-1761 800(1) 240.002 mm(9.4489 inch)

to240.033 mm(9.4501 inch)


236.80 mL(8.0 oz)

110.012 mm(4.3312inch)to

110.028 mm(4.3318inch)

280.000 mm(11.024 inch)

130.000 mm(5.1181 inch)

154-3032 820 280.002 mm(11.0237 inch)

to280.032 mm(11.0249 inch)

Double N/A 130.028 mm(5.1192 inch)

to130.051 mm(5.1201inch)

(1) Inboard bearing(2) Outboard bearing(3) 109-7687 bearing is preferred.(4) This bearing is a spherical roller bearing. This bearing is greased from the bracket’s front side. All of the other bearings are ball bearings.(2) This bearing is on the same end as the exciter.(3) This bearing is on the drive end of the generator.

i01219565

Bearing Temperature -Measure/RecordSMCS Code: 4471-082-TA

Bearing temperature detectors are optional onall SR4B generators. These detectors are 100ohm resistance temperature detectors. Bearingtemperature detectors are used with equipmentthat has been provided by the customer in orderto measure the bearing temperature. Bearingtemperature detectors may help to prevent prematurebearing failure.

i02509091

Belts - Inspect/Adjust/ReplaceSMCS Code: 1357-025; 1357-040; 1357-510

InspectionInspect the alternator belt and the fan drive belts forwear and for cracking. Replace the belts if the beltsare not in good condition.

Check the belt tension according to the information inthe Service Manual, “Specifications”.

Slippage of loose belts can reduce the efficiencyof the driven components. Vibration of loose beltscan cause unnecessary wear on the followingcomponents:

• Belts

• Pulleys

• Bearings

If the belts are too tight, unnecessary stress is placedon the components. This reduces the service life ofthe components.


Carburetor Air/Fuel Ratio - Check/Adjust

Adjusting the Alternator Belt

g01092641Illustration 62Typical alternator

(1) Mounting bolt(2) Adjusting nuts(3) Mounting bolt

1. Remove the drive belt guard.

2. Loosen mounting bolt (1), adjusting nuts (2) andmounting bolt (3).

3. Turn adjusting nuts (2) in order to increase ordecrease the drive belt tension.

4. Tighten adjusting nuts (2). Tighten mounting bolt(3). Tighten mounting bolt (1). For the propertorque, see the Service Manual, “Specifications”module.

5. Reinstall the drive belt guard.

If new drive belts are installed, check the drive belttension again after 30 minutes of engine operation atthe rated rpm.

Adjusting the Fan Drive Belt1. Loosen the mounting bolt for the pulley.

2. Loosen the adjusting nut for the pulley.

3. Move the pulley in order to adjust the belt tension.

4. Tighten the adjusting nut.

5. Tighten the mounting bolt.

ReplacementFor applications that require multiple drive belts,replace the drive belts in matched sets. Replacingone drive belt of a matched set will cause the newdrive belt to carry more load because the older drivebelts are stretched. The additional load on the newdrive belt could cause the new drive belt to fail.

i01005891

Carburetor Air/Fuel Ratio -Check/AdjustSMCS Code: 1266-535; 1266

An engine failure may occur if the air/fuel ratio isnot appropriate for the fuel and for the operatingconditions. The service life of the turbocharger, of thevalves, and of the other components may be reduced.

Ensure that the carburetor is adjusted properly sothat the air/fuel ratio is correct.

For information on adjusting the carburetor, refer tothe Service Manual, “Systems Operation/Testingand Adjusting”, or refer to the Special Instruction,“Installation and Initial Start-Up Procedure”.

i01762721

Control Panel - InspectSMCS Code: 4490-040; 7451-040

Inspect the condition of the panel. If a component isdamaged, ensure that the component is repaired orthat the component is replaced. If equipped, ensurethat the electronic displays are operating properly.

Inspect the wiring for good condition. Ensure that thewiring connections are secure.

Record the Data and Review theDataIf equipped, check the gauges and check theindicators frequently during normal operation. Recordthe data in a log. Compare the new data to the datathat was previously recorded. Comparing the newdata to the recorded data will establish the normalgauge readings for the engine. A gauge reading thatis abnormal may indicate a problem with operationor with the gauge.

84 SEBU6682-08Maintenance SectionCooling System Coolant (NGEC) - Change

i02150881

Cooling System Coolant(NGEC) - ChangeSMCS Code: 1350-044

Clean the cooling system before the recommendedmaintenance interval if the following conditions exist:

• The engine overheats frequently.

• Foaming is observed.

• Oil has entered the cooling system and the coolantis contaminated.

Drain the Cooling System1. Stop the engine and allow the engine to cool.Ensure that the engine will not start when thecooling system is drained.


2. Loosen the cooling system filler cap slowly inorder to relieve any pressure. Remove the coolingsystem filler cap.

g00719046Illustration 64Drain plugs on the oil cooler, water pumps, and elbows

3. Open the cooling system drain valve. Remove thedrain plugs.

NOTICEDispose of used engine coolant properly or recycle.Various methods have been proposed to reclaim usedcoolant for reuse in engine cooling systems. The fulldistillation procedure is the only method acceptable byCaterpillar to reclaim the used coolant.

For information regarding the disposal and therecycling of used coolant, consult your Caterpillardealer or consult Dealer Service Tools Group:

Outside Illinois: 1-800-542-TOOLInside Illinois: 1-800-541-TOOLCanada: 1-800-523-TOOL

Clean the Cooling System1. After the cooling system has been drained, flushthe cooling system with clean water in order toremove any debris.

2. Close the cooling system drain valve. Clean thedrain plugs and install the plugs.

NOTICEUse of commercially available cooling system clean-ers may cause damage to cooling system compo-nents. Use only cooling system cleaners that are ap-proved for Caterpillar engines.


Cooling System Coolant (NGEC) - Change

NOTICEFill the cooling system no faster than 19 L (5 US gal)per minute to avoid air locks.

3. Fill the cooling system with a mixture of cleanwater and Caterpillar Fast Acting Cooling SystemCleaner. Add 0.5 L (1 pint) of cleaner per 15 L(4 US gal) of the cooling system capacity. Installthe cooling system filler cap.

4. Start the engine. Operate the engine for aminimum of 30 minutes with a coolant temperatureof at least 82 °C (180 °F).

5. Stop the engine and allow the engine to cool.Loosen the cooling system filler cap slowly inorder to relieve any pressure. Remove the coolingsystem filler cap. Open the cooling system drainvalve. Remove the drain plugs.

NOTICEImproper or incomplete rinsing of the cooling systemcan result in damage to copper and other metal com-ponents.

To avoid damage to the cooling system, make sureto completely flush the cooling system with clear wa-ter. Continue to flush the system until all signs of thecleaning agent are gone.

6. Allow the water to drain. Flush the cooling systemwith clean water until the water that drains isclean. Close the cooling system drain valve. Cleanthe drain plugs and install the plugs.

Cleaning a Cooling System thathas Heavy Deposits or PluggingNote: For the following procedure to be effective,there must be an active flow through the coolingsystem components.

1. After the cooling system has been drained, flushthe cooling system with clean water in order toremove any debris.

2. Close the cooling system drain valve. Clean thedrain plugs and install the plugs.

NOTICEUse of commercially available cooling system clean-ers may cause damage to cooling system compo-nents. Use only cooling system cleaners that are ap-proved for Caterpillar engines.


3. Fill the cooling system with a mixture of cleanwater and Caterpillar Fast Acting Cooling SystemCleaner. Add 0.5 L (1 pint) of cleaner per3.8 to 7.6 L (1 to 2 US gal) of the cooling systemcapacity. Install the cooling system filler cap.

4. Start the engine. Operate the engine for aminimum of 90 minutes with a coolant temperatureof at least 82 °C (180 °F).

5. Stop the engine and allow the engine to cool.Loosen the cooling system filler cap slowly inorder to relieve any pressure. Remove the coolingsystem filler cap. Open the cooling system drainvalve. Remove the drain plugs. Allow the waterto drain.

NOTICEImproper or incomplete rinsing of the cooling systemcan result in damage to copper and other metal com-ponents.

To avoid damage to the cooling system, make sureto completely flush the cooling system with clear wa-ter. Continue to flush the system until all signs of thecleaning agent are gone.

6. Flush the cooling system with clean water untilthe water that drains is clean. Close the coolingsystem drain valve. Clean the drain plugs andinstall the plugs.

Fill the Cooling System


Note: For information about the proper coolant touse and for the capacity of the cooling system,seethis Operation and Maintenance Manual, “RefillCapacities and Recommendations” (MaintenanceSection).

1. Fill the cooling system with coolant/antifreeze. Donot install the cooling system filler cap.

2. Start the engine. Operate the engine in order topurge the air from the cavities of the engine block.Allow the coolant to warm and allow the coolantlevel to stabilize. Stop the engine.

86 SEBU6682-08Maintenance SectionCooling System Coolant Level - Check

3. Check the coolant level. Maintain the coolant tothe proper level on the sight gauge (if equipped).If a sight gauge is not equipped, maintain thecoolant within 13 mm (0.5 inch) below the bottomof the filler pipe.

4. Clean the cooling system filler cap. Inspect thegaskets of the cooling system filler cap. If thegaskets of the cooling system filler cap aredamaged, discard the old cooling system filler capand install a new cooling system filler cap. If thegaskets of the cooling system filler cap are notdamaged, use a 9S-8140 Pressurizing Pump inorder to pressure test the cooling system filler cap.The correct pressure is stamped on the face ofthe cooling system filler cap. If the cooling systemfiller cap does not maintain the correct pressure,install a new cooling system filler cap.

5. Start the engine. Inspect the cooling system forleaks and for proper operating temperature.

i01197583

Cooling System Coolant Level- CheckSMCS Code: 1350-535-FLV

Check the coolant level when the engine is stoppedand cool.

g00285520Illustration 65Cooling system filler cap

Pressurized System: Hot coolant can cause seri-ous burns. To open the cooling system filler cap,stop the engine and wait until the cooling systemcomponents are cool. Loosen the cooling systempressure cap slowly in order to relieve the pres-sure.

1. Remove the cooling system filler cap slowly inorder to relieve pressure.

2. Maintain the coolant level within 13 mm (0.5 inch)of the bottom of the filler pipe. If the engine isequipped with a sight glass, maintain the coolantlevel to the proper level in the sight glass.

g00103639Illustration 66Typical filler cap gaskets

3. Clean the cooling system filler cap and check thecondition of the filler cap gaskets. Replace thecooling system filler cap if the filler cap gaskets aredamaged. Reinstall the cooling system filler cap.

4. Inspect the cooling system for leaks.

i02064894

Cooling System CoolantSample (Level 1) - ObtainSMCS Code: 1350-008; 1395-008; 1395-554; 7542

NOTICEAlways use a designated pump for oil sampling, anduse a separate designated pump for coolant sampling.Using the same pump for both types of samples maycontaminate the samples that are being drawn. Thiscontaminate may cause a false analysis and an incor-rect interpretation that could lead to concerns by bothdealers and customers.

For conventional heavy-duty coolant/antifreeze,check the concentration of supplemental coolantadditive (SCA) regularly. The concentration of SCAcan be checked with an S·O·S coolant analysis(Level 1).

Obtain the sample of the coolant as close as possibleto the recommended sampling interval. In orderto receive the full effect of S·O·S analysis, youmust establish a consistent trend of data. In orderto establish a pertinent history of data, performconsistent samplings that are evenly spaced.Supplies for collecting samples can be obtained fromyour Caterpillar dealer.


Cooling System Coolant Sample (Level 2) - Obtain

Use the following guidelines for proper sampling ofthe coolant:

• Never collect samples from expansion bottles.

• Never collect samples from the drain for a system.

• Keep the unused sampling bottles stored in plasticbags.

• Keep the lids on empty sampling bottles until youare ready to collect the sample.

• Complete the information on the label for thesampling bottle before you begin to take thesamples.

• Obtain coolant samples directly from the coolantsample port. You should not obtain the samplesfrom any other location.

• In order to avoid contamination, immediately placethe sample in the tube that is provided for mailing.

Submit the sample for Level 1 analysis.

Note: Level 1 results may indicate a need forLevel 2 Analysis.

For additional information about coolant analysis,see the Special Publication, SEBU6400, “CaterpillarGas Engine Lubricant, Fuel and CoolantRecommendations” or consult your Caterpillar dealer.

i02168823

Cooling System CoolantSample (Level 2) - ObtainSMCS Code: 1350-008; 1395-008; 1395-554; 7542

NOTICEAlways use a designated pump for oil sampling, anduse a separate designated pump for coolant sampling.Using the same pump for both types of samples maycontaminate the samples that are being drawn. Thiscontaminate may cause a false analysis and an incor-rect interpretation that could lead to concerns by bothdealers and customers.

Obtain the sample of the coolant as close as possibleto the recommended sampling interval. Suppliesfor collecting samples can be obtained from yourCaterpillar dealer.

Refer to this Operation and Maintenance Manual,“Cooling System Coolant Sample (Level 1) - Obtain”(Maintenance Section) for the guidelines for propersampling of the coolant.

Submit the sample for Level 2 analysis.

For additional information about coolant analysis,see the Special Publication, SEBU6400, “CaterpillarGas Engine Lubricant, Fuel, and CoolantRecommendations” or consult your Caterpillar dealer.

i02017557

Cooling System SupplementalCoolant Additive (SCA) -Test/AddSMCS Code: 1352-045; 1395-081

Cooling system coolant additive contains alkali.To help prevent personal injury, avoid contact withthe skin and eyes. Do not drink cooling systemcoolant additive.

Note: Caterpillar recommends an S·O·S coolantanalysis (Level 1).

Test the Concentration of the SCA

Coolant/Antifreeze and SCA

NOTICEDo not exceed the recommended six percent supple-mental coolant additive concentration.

Test the concentration of the SCA with the 8T-5296Coolant Conditioner Test Kit. Follow the instructionsthat are provided in the kit.

Water and SCA

NOTICEDo not exceed the recommended eight percent sup-plemental coolant additive concentration.

Test the concentration of the SCA with the 8T-5296Coolant Conditioner Test Kit. Use the instructionsthat follow:

1. Fill the syringe to the “1.0 ml” mark with thecoolant.

2. Dispense the 1.0 mL coolant sample from thesyringe into the empty mixing bottle.

3. Add tap water to the mixing bottle in order to bringthe level up to the “10 ml” mark. Place the cap onthe bottle and shake the bottle.

88 SEBU6682-08Maintenance SectionCrankcase Blowby - Measure/Record

4. Add 2 to 3 drops of the “NITRITE INDICATORSOLUTION B” to the mixing bottle. Move the bottlein a circular motion in order to mix the solution.

5. Add 1 drop of “NITRITE TEST SOLUTION A” tothe mixing bottle. Move the bottle in a circularmotion in order to mix the solution.

6. Repeat 5 until the solution changes color from redto light gray, green, or blue. Record the number ofdrops of “NITRITE TEST SOLUTION A” that wererequired to cause the color change.

7. Use Table 23 to interpret the results.

Table 23

Number ofDrops

Concentrationof SCA

MaintenanceRequired

Less than 25 Less than therecommendedconcentration ofSCA

Add SCA.Retest thecoolant.

25 to 30 Therecommendedconcentration ofSCA

None

More than 30 More than therecommendedconcentration ofSCA

Remove thecoolant.Replace withwater onlyRetest thecoolant.

Add the SCA, If Necessary

Pressurized System: Hot coolant can cause seri-ous burns. To open the cooling system filler cap,stop the engine and wait until the cooling systemcomponents are cool. Loosen the cooling systempressure cap slowly in order to relieve the pres-sure.

1. Remove the cooling system filler cap slowly.

Note: Always dispose of fluids according to localregulations.

2. If necessary, drain some coolant in order to allowspace for the addition of the SCA.

NOTICEExcessive supplemental coolant additive concentra-tion can form deposits on the higher temperature sur-faces of the cooling system, reducing the engine’sheat transfer characteristics. Reduced heat transfercould cause cracking of the cylinder head and otherhigh temperature components.

Excessive supplemental coolant additive concentra-tion could also result in blockage of the heat exchang-er, overheating, and/or accelerated wear of the waterpump seal.

Do not exceed the recommended amount of supple-mental coolant additive concentration.

3. Add the proper amount of SCA. The concentrationof the SCA depends on the type of coolant thatis used. To determine the proper amount, seethis Operation and Maintenance Manual, “RefillCapacities and Recommendations” topic.

4. Clean the cooling system filler cap. Install thecooling system filler cap.

i01333307

Crankcase Blowby -Measure/RecordSMCS Code: 1317

Note: For a new G3400 Engine, the typical range forcrankcase blowby is approximately 22 to 37 L/Bkw-hr(0.6 to 1.0 cu ft/Bhp-hr).

Measure the crankcase blowby of new engines.Record the data. Continue to periodically measurethe blowby. Comparing the recorded data to the newdata provides information about the condition of theengine.

Note: Crankcase blowby is one of the three factorsthat help to determine the major overhaul interval.For more information, see this Operation andMaintenance manual, “Overhaul (Major)” topic(Maintenance Section).

After a new engine is used for a short time, theblowby can decrease as the piston rings are seated.The blowby will gradually increase as the followingcomponents show wear:

• piston rings

• cylinder liners


Crankshaft Vibration Damper - Inspect

Note: A problem with the piston rings causes theoil to deteriorate rapidly. Information regarding thecondition of the piston rings can be obtained fromthe measurement of the blowby and the results ofoil analysis.

The blowby of a worn engine may exceed the blowbyof a new engine by two times or more.

A sudden increase in blowby could indicate a brokenpiston ring. The following conditions are otherpotential sources of blowby:

• Worn valve guides

• A turbocharger seal that leaks

A rebuilt engine can have a high blowby due to thefollowing factors:

• The piston rings are not seated properly.

• Worn parts such as valve guides were not replaced.

Excessive blowby may indicate the need for anoverhaul. By keeping a record of the results, agradual increase in the amount of the blowby will benoted until the amount has become excessive.

To measure the blowby, use the 8T-2700 Blowby/AirFlow Indicator. Refer to Special Instruction,SEHS8712, “Using the 8T-2700 Blowby/AirflowIndicator Group”. The instruction is provided with thetool.

Keep a record of the results.

For more information, see the Service Manual,“Systems Operation/Testing and Adjusting”. Forassistance, consult your Caterpillar dealer.

i01333457

Crankshaft Vibration Damper- InspectSMCS Code: 1205-040

Damage to the crankshaft vibration damper or failureof the crankshaft vibration damper can increasetorsional vibrations. This can result in damage tothe crankshaft and to other engine components. Adeteriorating damper can cause excessive gear trainnoise at variable points in the speed range.

The damper is mounted to the crankshaft which islocated behind the belt guard on the front of theengine.

Visconic DamperThe visconic damper has a weight that is locatedinside a fluid filled case. The weight moves in thecase in order to limit torsional vibration.

Inspect the damper for evidence of fluid leaks. Ifa fluid leak is found, determine the type of fluid.The fluid in the damper is silicone. Silicone hasthe following characteristics: transparent, viscous,smooth, and adhesive.

If the fluid leak is oil, inspect the crankshaft seals forleaks. If a leak is observed, replace the crankshaftseals.

Inspect the damper and repair or replace the damperfor any of the following reasons:

• The damper is dented, cracked, or leaking.

• The paint on the damper is discolored from heat.

• The engine has had a failure because of a brokencrankshaft.

• Analysis of the oil has revealed that the front mainbearing is badly worn.

• There is a large amount of gear train wear that isnot caused by a lack of oil.

Refer to the Service Manual or consult yourCaterpillar dealer for information about damperreplacement.

i01664707

Cylinder Pressure -Measure/RecordSMCS Code: 1223-082-CC; 1223; 7450-082

Measure the cylinder pressure of new engines.Record the data. Continue to periodically measurethe cylinder pressure. Comparing the recorded datato the new data provides information about thecondition of the engine.

Cylinder pressure can be measured during inspectionof the spark plugs. Use the following guidelines forchecking the cylinder pressure:

• Remove all of the spark plugs.

• Fully open the throttle plate.

• Minimize the cranking time to 3 or 4 revolutions.This will enable a maximum consistent crankingspeed for the check. Also, the battery power willbe conserved.

90 SEBU6682-08Maintenance SectionDriven Equipment - Check

A loss of cylinder pressure or a change of pressurein one or more cylinders may indicate the followingconditions. These conditions may indicate a problemwith lubrication:

• Excessive deposits

• Guttering of valves

• A broken valve

• A piston ring that sticks

• A broken piston ring

• Worn piston rings

• Worn cylinder liners

If the cylinder pressure has risen by one or morecompression ratios, the engine needs a top endoverhaul in order to remove deposits. Failure toremove the deposits will increase the chance fordetonation. Severe guttering of the valves will occur.

To measure the cylinder pressure, use the 193-5859Cylinder Pressure Gauge Gp. Follow the procedurein the Special Instruction, NEHS0798 that is includedwith the gauge group. Record the pressure foreach cylinder. Use the Operation and MaintenanceManual, “Valve Data Sheet” (Reference MaterialsSection).

Illustration 67 is a graph of typical cylinder pressuresfor engines with different compression ratios.


(Y) Cylinder pressure in kPa(X) Compression ratio(1) Normal range for cylinder pressure

i00449093

Driven Equipment - CheckSMCS Code: 3279-535

To minimize bearing problems and vibration of theengine crankshaft and the driven equipment, thealignment between the engine and driven equipmentmust be maintained properly.

Check the alignment according to the instructionsthat are provided by the following manufacturers:

• Caterpillar

• OEM of the coupling

• OEM of the driven equipment


Driven Equipment - Inspect/Replace/Lubricate

i00935098

Driven Equipment -Inspect/Replace/LubricateSMCS Code: 3279-040

Observe the driven equipment during operation. Lookfor the following items:

• Unusual noise and vibration

• Loose connections

• Damaged parts

Perform any maintenance that is recommendedby the OEM of the driven equipment. Refer to theliterature of the OEM of the driven equipment for thefollowing service instructions.

• Inspection

• Lubricating grease and lubricating oil requirements

• Specifications for adjustment

• Replacement of components

• Requirements for ventilation

i01664717

Engine - CleanSMCS Code: 1000-070

Personal injury or death can result from high volt-age.

Moisture could create paths of electrical conduc-tivity.

Make sure the unit is off line (disconnected fromutility and/or other generators), locked out andtagged "Do Not Operate".

NOTICEWater or condensation can cause damage to gen-erator components. Protect all electrical componentsfrom exposure to water.

NOTICEAccumulated grease and oil on an engine is a fire haz-ard. Keep the engine clean. Remove debris and fluidspills whenever a significant quantity accumulates onthe engine.

Steam cleaning the engine will remove accumulatedoil and grease. A clean engine provides the followingbenefits:

• Easy detection of fluid leaks

• Maximum heat transfer characteristics

• Ease of maintenance

Note: For more information on cleaning and dryingelectric generators, refer to Special Instruction,SEHS9124, “Cleaning and Drying of Electric SetGenerators”.

i01749609

Engine Air Cleaner Element -ReplaceSMCS Code: 1051-510; 1054-510

NOTICENever run the engine without an air cleaner elementinstalled. Never run the engine with a damaged aircleaner element. Do not use air cleaner elements withdamaged pleats, gaskets or seals. Dirt entering theengine causes premature wear and damage to enginecomponents. Air cleaner elements help to prevent air-borne debris from entering the air inlet.

NOTICENever service the air cleaner element with the enginerunning since this will allow dirt to enter the engine.

Servicing the Air Cleaner ElementsIf the air cleaner element becomes plugged, the airpressure can split the filter material of the element.Unfiltered air will drastically accelerate internalengine wear. Your Caterpillar dealer has the properair cleaner elements for your application.

The air cleaner may be mounted high above theengine. If necessary, use a ladder or a platform toreach the air cleaner.

• Check the precleaner (if equipped) daily foraccumulation of dirt and debris. Remove any dirtand debris, as needed.

92 SEBU6682-08Maintenance SectionEngine Air Cleaner Element - Replace

• Operating conditions (dust, dirt and debris) mayrequire more frequent service of the air cleanerelement.

• The air cleaner element may be cleaned up tosix times if the element is properly cleaned andinspected.

• The air cleaner element should be replaced at leastone time per year. This replacement should beperformed regardless of the number of cleanings.

Replace the dirty paper elements with cleanelements. Before installation, thoroughly inspect theelement for tears and/or holes in the filter material.Inspect the gasket or the seal of the element fordamage. Maintain a supply of suitable elements forreplacement purposes.


Fasteners for the air cleaner cover


(1) Cover(2) Element(3) Air inlet

1. Release the fasteners for cover (1).

2. Remove the cover and element (2).

3. Cover air inlet (3) with tape in order to keep dirtout.

4. Clean the inside of the cover and the body witha clean, dry cloth.

5. Remove the tape for the air inlet. Install a newelement or a clean element.

6. Install the cover.

7. If necessary, reset the air cleaner service indicator.

Cleaning the Primary Air CleanerElementsThe primary air cleaner element can be used upto six times if the element is properly cleaned andinspected. When the element is cleaned, check thefilter material for rips or tears. Replace the elementat least one time per year regardless of the numberof cleanings.

Use clean elements while dirty elements are beingcleaned.

NOTICEDo not clean the air cleaner elements by bumping ortapping. This could damage the seals. Do not use el-ements with damaged pleats, gaskets or seals. Dam-aged elements will allow dirt to pass through. Enginedamage could result.

Visually inspect the elements before cleaning. Inspectthe elements for damage to the seal, the gaskets,and the outer cover. Discard any damaged elements.

Air cleaner elements can be cleaned with pressurizedair and with a vacuum.

Pressurized Air

Pressurized air can be used to clean elementsthat have not been cleaned more than two times.Pressurized air will not remove deposits of carbonand oil. Use filtered, dry air with a maximum pressureof 207 kPa (30 psi).



Engine Air Cleaner Service Indicator - Inspect

Note:When the elements are cleaned, always beginwith the clean side (inside) in order to force dirtparticles toward the dirty side (outside).

Aim the hose so that the air flows inside the elementalong the length of the filter in order to help preventdamage to the paper pleats. Do not aim the streamof air directly at the primary air cleaner element. Dirtcould be forced into the pleats.

Note: Refer to “Inspecting the Primary Air CleanerElements”.

Vacuum Cleaning

Vacuum cleaning is a good method for cleaningelements which require daily cleaning because of adry, dusty environment. Cleaning with pressurized airis recommended prior to vacuum cleaning. Vacuumcleaning will not remove deposits of carbon and oil.

Note: Refer to “Inspecting the Primary Air CleanerElements”.

Inspecting the Primary Air CleanerElements


Inspect the clean, dry element. Use a 60 watt bluelight in a dark room or in a similar facility. Placethe blue light in the element. Rotate the element.Inspect the element for tears and/or holes. Inspectthe element for light that may show through the filtermaterial. If it is necessary in order to confirm theresult, compare the element to a new element thathas the same part number.

Do not use an element that has any tears and/orholes in the filter material. Do not use an element withdamaged pleats, gaskets or seals. Discard damagedelements.

Storing Primary Air Cleaner Elements

If an element that passes inspection will not be usedimmediately, store the element for future use.


Do not use paint, a waterproof cover, or plastic as aprotective covering for storage. Restricted air flowmay result. To protect against dirt and damage, wrapthe elements in Volatile Corrosion Inhibited (VCI)paper.

Place the element into a cardboard box for storage.For identification, mark the outside of the containerand mark the element. Include the followinginformation:

• Date of cleaning

• Number of cleanings

Store the container in a dry location.

For more detailed information on cleaning the primaryair cleaner element, refer to Special Publication,SEBF8062, “Procedure to Inspect and Clean AirFilters”.

i01505252

Engine Air Cleaner ServiceIndicator - InspectSMCS Code: 7452-040

A service indicator may be mounted on the aircleaner element or in a remote location.

94 SEBU6682-08Maintenance SectionEngine Air Precleaner - Clean

g00517797Illustration 73Service indicator

Some engines may be equipped with a differentservice indicator.

Observe the service indicator. Clean the air cleanerelement or replace the element when the followingconditions occur:

• The yellow diaphragm enters the red zone.

• The red piston locks in the visible position.

• The air restriction reaches 3.7 kPa(15 inches of H2O).

Inspect the service indicator daily for cracks, holes, orloose fittings. If any of these conditions are present,repair the service indicator or replace the serviceindicator.

Test the Service IndicatorService indicators are important instruments.

• Check for ease of resetting. The service indicatorshould reset in less than three pushes.

• Check the movement of the yellow core when theengine is accelerated to the engine rated rpm.The yellow core should latch approximately at thegreatest vacuum that is attained.

If the service indicator does not reset easily, or if theyellow core does not latch at the greatest vacuum,replace the service indicator. If the new serviceindicator will not reset, the fitting for the serviceindicator may be plugged.

g00351792Illustration 74Porous filter

A porous filter is part of a fitting that is used formounting of the service indicator. Inspect the filterfor cleanliness. Clean the filter, if necessary. Usecompressed air or a clean, nonflammable solvent.

The service indicator may need to be replacedfrequently in environments that are severely dusty.Replace the service indicator annually regardlessof the operating conditions. Replace the serviceindicator when the engine is overhauled, andwhenever major engine components are replaced.

Note: When a new service indicator is installed,excessive force may crack the top of the serviceindicator. Tighten the service indicator to a torqueof 2 N·m (18 lb in).

i01397717

Engine Air Precleaner - CleanSMCS Code: 1055-070

g00736588Illustration 75Typical precleaner(1) Wing nut(2) Cover(3) Body


Engine Crankcase Breather - Clean

Remove wing nut (1) and cover (2). Check for anaccumulation of dirt and debris in body (3). Clean thebody, if necessary.

After cleaning the precleaner, install cover (2) andwing nut (1).

Note: When the engine is operated in dustyapplications, more frequent cleaning is required.

i02263740

Engine Crankcase Breather -CleanSMCS Code: 1317-070

NOTICEPerform this maintenance with the engine stopped.

If the crankcase breather is not maintained on aregular basis, the crankcase breather will becomeplugged. A plugged crankcase breather will causeexcessive crankcase pressure that may causecrankshaft seal leakage.


Typical example

(1) Hose clamp(2) Breather assembly(3) Retaining clamp(4) Seal

1. Loosen hose clamp (1) and remove the hose frombreather assembly (2).

2. Loosen retaining clamp (3). Remove the breatherassembly and seal (4).

3. Wash the breather element in solvent that is cleanand nonflammable. Allow the breather element todry before installation.

4. Install a breather element that is clean and dry.Install the seal, the breather assembly, and theclamp. Refer to the Specifications, SENR3130 inorder to locate the proper torques.

5. Install the hose. Install the hose clamp. Refer tothe Specifications, SENR3130 in order to locatethe proper torques.

i02017664

Engine Mounts - CheckSMCS Code: 1152-535


(1) Mounting bolts for the engine(2) Mounting bolts for the generator(3) Levelling bolts for the isolators

Misalignment of the engine and the driven equipmentwill cause extensive damage. Excessive vibrationcan lead to misalignment. Excessive vibration of theengine and the driven equipment can be caused bythe following conditions:

• Improper mounting

• Loose bolts

• Deterioration of the isolators

Ensure that the mounting bolts are tightenedto the proper torque. For standard torques, seeSpecifications, SENR3130, “Torque Specifications”.

Ensure that the isolators are free of oil andcontamination. Inspect the isolators for deterioration.Ensure that the bolts for the isolators are tightened tothe proper torque.

Replace any isolator that shows deterioration. Formore information, see the literature that is providedby the OEM of the isolators. Also see the Applicationand Installation Guide for the engine. Consult yourCaterpillar dealer for assistance.

96 SEBU6682-08Maintenance SectionEngine Oil Filter (Auxiliary) - Change

i02017678

Engine Oil Filter (Auxiliary) -ChangeSMCS Code: 1318

Note: An auxiliary oil filter system enables the oilcapacity of the engine to be increased. Use of theauxiliary oil filter elements is not recommended.

Perform this procedure after the oil has been drainedfrom the auxiliary oil filter housing.

g00787079Illustration 78Auxiliary oil filter housing

(1) Vent plug(2) Drain plug

1. If the engine is equipped with an auxiliary oil filtersystem, remove vent plug (1). Remove drain plug(2). Allow the oil to drain. After the oil has drained,clean the drain plug.


(1) Vent plug(2) Drain plug(3) Nut(4) Washer(5) Plug(6) Bolt(7) Cover(8) Cover gasket(9) Nut(10) Spring retainer(11) Spring(12) Bolt(13) Washer(14) Spider(15) Plate

1. Remove 12 nuts (3), washers (4), and bolts (6).

2. Remove cover (7) and gasket (8). Do not damagethe gasket.

Possible injury can occur during the removal ofthe nut, the spring retainer, and the spring. Springforce will be released when the nut and the springretainer are removed. Be prepared to hold thespring retainer as the nut is loosened.

3. Remove nut (9), spring retainer (10), and spring(11). Hold spring retainer (10) as nut (9) isloosened.


Engine Oil Level - Check

4. Remove bolt (12). Remove washer (13) andspider (14). Remove plate (15).

5. Remove the oil filter elements if the oil filters havebeen installed. Clean the inside of the oil filterhousing.

Inspect the oil filter elements if the oil filters havebeen installed. For instructions on inspectingthe oil filter elements, refer to the Operation andMaintenance Manual, “Engine Oil Filter - Change”topic (Maintenance Section).

6. Ensure that plug (5) is tight.

7. Install drain plug (2). Tighten the drain plug to70 ± 14 N·m (50 ± 10 lb ft).

Note: Use of the auxiliary oil filter elements is notrequired.

8. If the use of auxiliary oil filter elements is desired,install new elements.

9. Install plate (15), spider (14), washer (13), andbolt (12).

10. Install spring (11) on spider (14). Install springretainer (10) and nut (9) on bolt (12).

11.Tighten nut (9) in order to compress spring (11)until the spring retainer bottoms out on bolt (12).Do not overtighten the nut.

12. Fill the oil filter housing with oil. For the correctamount of oil, refer to the Operation andMaintenance Manual, “Refill Capacities andRecommendations” topic (Maintenance Section).

13. Inspect cover gasket (8) for tears, breaks, or otherdamage. If the cover gasket is damaged, replacethe old cover gasket with a new cover gasket.Install cover gasket (8). Install cover (7).

14. Install twelve bolts (6), washers (4), and nuts(3). Tighten nuts sequentially around the coveruntil the nuts are snug. Tighten the nuts to100 ± 15 N·m (75 ± 11 lb ft).

15. Install vent plug (1).

i02150939

Engine Oil Level - CheckSMCS Code: 1348-535-FLV

The most accurate check of the oil level isperformed when the engine is stopped. Perform thismaintenance on a surface that is as level as possible.

g00788953Illustration 80(1) Oil level gauge (dipstick)(2) Oil filler

g00735162Illustration 81(3) “ENGINE STOPPED” side(4) “LOW IDLE” side(5) “ADD” mark(6) “FULL” mark

1. Ensure that oil level gauge (1) is seated.

a. If the engine is stopped, remove oil levelgauge (1). Observe the oil level on “ENGINESTOPPED” side (3).

b. If the engine is operating, reduce the enginespeed to low idle. Remove oil level gauge (1)and observe the oil level on “LOW IDLE” side(4).

The oil level should be between “ADD” mark(5) and “FULL” mark (6).

98 SEBU6682-08Maintenance SectionEngine Oil Sample - Obtain

NOTICEEngine damage can occur if the crankcase is filledabove the “FULL” mark on the oil level gauge (dip-stick).

An overfull crankcase can cause the crankshaft to dipinto the oil. This will reduce the power that is devel-oped and also force air bubbles into the oil. Thesebubbles (foam) can cause the following problems: re-duction of the oil’s ability to lubricate, reduction of oilpressure, inadequate cooling, oil blowing out of thecrankcase breathers, and excessive oil consumption.

Excessive oil consumption will cause deposits to formon the pistons and in the combustion chamber. De-posits in the combustion chamber lead to the followingproblems: guttering of the valves, packing of carbonunder the piston rings, and wear of the cylinder liner.

If the oil level is above the “FULL” mark on the oil levelgauge, drain some of the oil immediately.

2. If necessary, remove oil filler cap (2) and addoil. For the correct oil to use, see this Operationand Maintenance Manual, “Refill Capacities andRecommendations” topic (Maintenance Section).Do not fill the crankcase above “FULL” mark (6).Clean the oil filler cap. Install the oil filler cap.

3. Record the amount of oil that is added. For thenext oil sample and analysis, include the totalamount of oil that has been added since theprevious oil sample. This will help to provide themost accurate oil analysis.

i01363663

Engine Oil Sample - ObtainSMCS Code: 1348-554-SM

In addition to a good preventive maintenanceprogram, Caterpillar recommends using S·O·S oilanalysis at regularly scheduled intervals in orderto monitor the condition of the engine and themaintenance requirements of the engine.

Obtain the Sample and the Analysis

Hot oil and hot components can cause personalinjury. Do not allow hot oil or hot components tocontact the skin.

Before taking the sample, complete the Label,PEEP5031 for identification of the sample. To helpobtain the most accurate analysis, provide thefollowing information:

• Engine model

• Service hours on the engine

• The oil’s hours of use

• The amount of oil that has been added since thelast oil change

To ensure that the sample is representative of theoil in the crankcase, obtain a warm, well mixed oilsample.

To avoid contamination of the oil samples, the toolsand the supplies that are used for obtaining oilsamples must be clean.

Caterpillar recommends using the sampling valvein order to obtain oil samples. The quality andthe consistency of the samples is better when thesampling valve is used. The location of the samplingvalve allows oil that is flowing under pressure to beobtained during normal engine operation.

The 8T-9190 Fluid Sampling Bottle Group isrecommended for use with the sampling valve. Thebottle group includes the parts that are needed forobtaining oil samples. Instructions are also provided.

NOTICEDo not use the same vacuum sampling pump for ex-tracting oil samples that is used for extracting coolantsamples.

A small residue of either type sample may remain inthe pump and may cause a false positive analysis forthe sample being taken.

Always use a designated pump for oil sampling and adesignated pump for coolant sampling.

Failure to do so may cause a false analysis whichcould lead to customer and dealer concerns.

If the engine is not equipped with a sampling valve,use the 1U-5718 Vacuum Pump. The pump isdesigned to accept sampling bottles. Disposabletubing must be attached to the pump for insertioninto the sump.

For instructions, see Special Publication, PEHP6001,“How To Take A Good Oil Sample”. Consult yourCaterpillar dealer for complete information andassistance in establishing an S·O·S program for yourengine.


Engine Oil and Filter - Change

i02523743

Engine Oil and Filter - ChangeSMCS Code: 1318-510

Hot oil and hot components can cause personalinjury. Do not allow hot oil or hot components tocontact the skin.

NOTICEEnsure that the engine is stopped before performingthis procedure. Attach a DONOTOPERATE tag to thestarting controls.

Do not drain the oil when the engine is cold. As the oilcools, suspended waste particles settle on the bottomof the oil pan. The waste particles are not removedwhen the cold oil is drained. Drain the crankcase withthe oil warm, immediately after the engine is stopped.This method of draining allows the waste particlesthat are suspended in the oil to be drained.

Failure to follow this recommended procedure willcause the waste particles to be recirculated throughthe engine lubrication system with the new oil.


(1) Oil filler cap(2) Oil filter(3) Oil level gauge (dipstick)(4) Oil drain

Drain the Engine Oil1. After the engine has been operated at normaloperating temperature, STOP the engine.

NOTICECare must be taken to ensure that fluids are containedduring performance of inspection, maintenance, test-ing, adjusting and repair of the product. Be prepared tocollect the fluid with suitable containers before open-ing any compartment or disassembling any compo-nent containing fluids.

Refer to Special Publication, NENG2500, “CaterpillarDealer Service Tool Catalog” for tools and suppliessuitable to collect and contain fluids on Caterpillarproducts.

Dispose of all fluids according to local regulations andmandates.

2. Drain the oil.

a. If the engine has an oil drain valve, open thevalve in order to drain the oil. After the oil hasdrained, close the valve.

b. If the engine does not have a drain valve,remove an oil drain plug. Allow the oil to drain.

Replace the Oil Filter1. Remove the oil filter with a 1U-8760 ChainWrench.

2. Cut the oil filter open with a 4C-5084 Oil FilterCutter. Break apart the pleats and inspect the oilfilter for metal debris.

An excessive amount of metal debris in the oilfilter may indicate early wear or a pending failure.

Use a magnet to differentiate between the ferrousmetals and the nonferrous metals that are found inthe oil filter element. Ferrous metals may indicatewear on the steel and cast iron parts of the engine.

Nonferrous metals may indicate wear on thealuminum parts, brass parts or bronze parts ofthe engine. Parts that may be affected includethe following items: main bearings, rod bearings,turbocharger bearings, and cylinder heads.

Aluminum debris may indicate problems with thebearings of the front gears. If you find aluminumdebris, inspect the vibration damper and the idlergear bearings.

Due to normal wear and friction, it is notuncommon to find small amounts of debris in theoil filter element. If an excessive amount of debrisis found in the oil filter element, consult yourCaterpillar dealer in order to arrange for furtheroil analysis.

100 SEBU6682-08Maintenance SectionEngine Oil and Filter - Change

g00103713Illustration 83Typical filter mounting base and filter gasket

3. Clean the sealing surface of the filter mountingbase. Ensure that all of the old oil filter gasket isremoved.

NOTICECaterpillar oil filters are built to Caterpillar speci-fications. Use of an oil filter not recommended byCaterpillar could result in severe engine damage tothe engine bearings, crankshaft, etc., as a result ofthe larger waste particles from unfiltered oil enteringthe engine lubricating system. Only use oil filtersrecommended by Caterpillar.

4. Apply clean engine oil to the new oil filter gasket.

NOTICEDo not fill the oil filters with oil before installing them.This oil would not be filtered and could be contaminat-ed. Contaminated oil can cause accelerated wear toengine components.

5. Install the oil filter. Tighten the oil filter until theoil filter gasket contacts the base. Tighten the oilfilter by hand according to the instructions that areshown on the oil filter. Do not overtighten the oilfilter.

Fill the Engine Crankcase

NOTICEOnly use oils that are recommended by Caterpillar.For the proper oil to use, refer to this Operation andMaintenance Manual, “Refill Capacities and Recom-mendations” topic (Maintenance Section).

NOTICEEngine damage can occur if the crankcase is filledabove the “FULL” mark on the oil level gauge (dip-stick).

An overfull crankcase can cause the crankshaft to dipinto the oil. This will reduce the power that is devel-oped and also force air bubbles into the oil. Thesebubbles (foam) can cause the following problems: re-duction of the oil’s ability to lubricate, reduction of oilpressure, inadequate cooling, oil blowing out of thecrankcase breathers, and excessive oil consumption.

Excessive oil consumption will cause deposits to formon the pistons and in the combustion chamber. De-posits in the combustion chamber lead to the followingproblems: guttering of the valves, packing of carbonunder the piston rings, and wear of the cylinder liner.

If the oil level is above the “FULL” mark on the oil levelgauge, drain some of the oil immediately.

1. Remove the oil filler cap. Fill the crankcase withthe proper amount of oil. Refer to the Operationand Maintenance Manual, “Refill Capacities andRecommendations” topic (Maintenance Section).

NOTICETo prevent crankshaft damage or bearing damage,crank the engine with the fuel supply line closed. Thiswill ensure that all of the oil filters are filled with oil be-fore the engine is started. Do not crank the engine formore than 30 seconds. Allow the starting motor to coolfor two minutes before cranking again.

2. Close the fuel supply line. Crank the engine untilnormal oil pressure shows on the oil pressuregauge. Open the fuel supply line.

3. Start the engine according to this Operatingand Maintenance Manual, “Starting the Engine”procedure (Operation Section). Operate theengine at low idle rpm for two minutes.

This will ensure that the lubrication system has oiland that the oil filters are filled. Inspect the enginefor oil leaks.

4. Stop the engine and allow the oil to drain back tothe sump for a minimum of ten minutes.

5. Remove the oil level gauge and check the oillevel. Maintain the oil level between the “ADD”and “FULL” marks on the “ENGINE STOPPED”side of the oil level gauge.


Engine Performance - Test

i01042067

Engine Performance - TestSMCS Code: 1000-081

Operate the engine for a minimum of two hours at aminimum load of 60 percent.

• Monitor the operation of the generator set.

• Observe the gauges. Ensure that the gauges arein the normal ranges.

• Record the data. Maintain a record of the data forthe engine performance.

i00626013

Engine Protective Devices -CheckSMCS Code: 7400-535

Alarms and shutoffs must function properly. Alarmsprovide timely warning to the operator. Shutoffs helpto prevent damage to the engine. It is impossibleto determine if the engine protective devices arein good working order during normal operation.Malfunctions must be simulated in order to test theengine protective devices.

A calibration check of the engine protective deviceswill ensure that the alarms and shutoffs activateat the setpoints. Ensure that the engine protectivedevices are functioning properly.

NOTICEDuring testing, abnormal operating conditions must besimulated.

The tests must be performed correctly in order to pre-vent possible damage to the engine.

To prevent damage to the engine, only authorizedservice personnel or your Caterpillar dealer shouldperform the tests.

Visual InspectionVisually check the condition of all gauges, sensorsand wiring. Look for wiring and components thatare loose, broken, or damaged. Damaged wiringor components should be repaired or replacedimmediately.

i01616208

Engine Speed/Timing Sensor -Clean/InspectSMCS Code: 1905-040; 1905-070; 1907-040;1907-070


Engine speed/timing sensor in the front cover for the timing disc

1. Remove the sensor from the cover. Check thecondition of the end of the magnet. Check forsigns of wear and contaminants.

2. Clean the metal shavings and other debris fromthe face of the magnet.

3. Install the sensor and adjust the sensor accordingto the engine’s Specifications.

i02526257

Engine Valve Lash -Inspect/AdjustSMCS Code: 1102-025

This maintenance is recommended by Caterpillaras part of a lubrication and preventive maintenanceschedule in order to help provide maximum enginelife.

NOTICEOnly qualified service personnel should perform thismaintenance. Refer to the Service Manual or yourCaterpillar dealer for the complete valve lash adjust-ment procedure.

Operation of Caterpillar engines with improper valveadjustments can reduce engine efficiency. This re-duced efficiency could result in excessive fuel usageand/or shortened engine component life.

102 SEBU6682-08Maintenance SectionEngine Valve Rotators - Inspect

Ensure that the engine can not be started whilethis maintenance is being performed. To help pre-vent possible injury, do not use the starting motorto turn the flywheel.

Hot engine components can cause burns. Allowadditional time for the engine to cool before mea-suring/adjusting valve lash clearance.

Ensure that the engine is stopped before measuringthe valve lash. To obtain an accurate measurement,allow the valves to cool before this maintenance isperformed.

Refer to the engine’s Specification manual for morethe valve lash settings, or the engine’s SystemsOperation/Testing and Adjusting manual for thesettings and the procedure.

i01765711

Engine Valve Rotators - InspectSMCS Code: 1109-040

NOTICEA valve rotator which does not operate properly willaccelerate valve face wear and valve seat wear andshorten valve life. If a damaged rotator is not replaced,valve face guttering could result and cause pieces ofthe valve to fall into the cylinder. This can cause pistonand cylinder head damage.

Note: Use of a platform may be necessary to reachthe engine valve rotators.

Perform this procedure after the valve lash has beenset.

1. Mark the tops of the valve rotators with apermanent marker. Note the position of the marks.

2. Install the valve covers. See the Service Manualfor the procedure.

3. Start the engine. Operate the engine for 5 minutes.Stop the engine.

4. Remove the valve covers. Observe the position ofthe marks that are on the valve rotators.

If a valve fails to rotate, consult your Caterpillardealer.

i01505507

Exhaust Bypass - InspectSMCS Code: 1057-040

For instructions on removal and installation, see theService Manual, “Disassembly and Assembly”.

1. Remove the exhaust bypass valve.

The exhaust bypass valve cover is under springcompression. To prevent personal injury, use cau-tion when removing the cover.

2. Disassemble the valve.

g00781274Illustration 85Exhaust bypass valve(1) Diaphragm(2) Valve stem(3) Breather

3. Inspect diaphragm (1). If the diaphragm is worn orcracked, replace the diaphragm.

4. Inspect valve stem (2) and the valve guide. If theparts are excessively worn, replace the parts.

5. Clean breather (3).

6. Assemble the valve.

7. Install the valve.


Exhaust Piping - Inspect

i00721010

Exhaust Piping - InspectSMCS Code: 1061-040

Hot engine components can cause injury fromburns. Before performing maintenance on theengine, allow the engine and the components tocool.

Inspect the components of the exhaust system.Repair the components or replace the components ifany of the following conditions occur:

• Damage

• Cracks

• Leaks


Consult your Caterpillar dealer for assistance.

Water Cooled Exhaust ManifoldsThe water cooled exhaust manifolds do not requiremaintenance unless excessive deposits build up inthe exhaust passages. Buildup of deposits causean increase in back pressure that will cause thefollowing conditions:

• Increased fuel consumption

• Reduced boost pressure

If excessive deposits build up in the exhaustpassages, clean the passages in order to removethe deposits.

i01505536

Fuel System Fuel FilterDifferential Pressure - CheckSMCS Code: 1261-535

A fuel filter differential pressure gauge must beinstalled in order to determine when the fuel filterrequires service. This gauge and the fuel filter aresupplied by the customer.

A fuel filter differential pressure gauge indicates thedifference in fuel pressure between the inlet sideand the outlet side of the fuel filter. The differentialpressure increases as the fuel filter becomesplugged.

Operate the engine at the rated speed and at thenormal operating temperature. Check the fuel filterdifferential pressure. Service of the fuel filter dependson the pressure of the fuel system:

• For low pressure gas fuel systems, service thefuel filter when the fuel filter differential pressurereaches 1.7 kPa (0.25 psi).

• For high pressure gas fuel systems, service thefuel filter when the fuel filter differential pressurereaches 34 kPa (5 psi).

For instructions, see Special Instruction, SEHS9298,“Installation and Maintenance of Gaseous FuelFilters”. Consult your Caterpillar dealer for assistance.

i02108745

Gas Pressure Regulator -CheckSMCS Code: 1270-535

Check the fuel pressure before the gas pressureregulator and after the gas pressure regulator. Table24 lists the fuel pressure that is required for the gaspressure regulator.

Table 24

Requirements for Fuel Pressure To the GasPressure Regulator

Fuel System Pressure

Low pressure gasNaturally Aspirated

10.3 to 34 ± 2 kPa(1.50 to 5 ± 0.25 psi)

High pressure gas 172 to 207 ± 7 kPa(25 to 30 ± 1 psi)

Pressure of the Fuel Supply To theCarburetorThe gas pressure regulator maintains a pressuredifferential between the air and the fuel that issupplied to the carburetor. After setting, the gaspressure regulator will maintain the pressuredifferential in response to changes in the air pressure.

104 SEBU6682-08Maintenance SectionGenerator - Dry

Use a water manometer for measuring the pressuredifferential. Obtain the measurement when theengine is operating at high idle rpm. After a loadis applied, the fuel pressure will usually decreaseby approximately 0.1 to 0.25 kPa (0.50 to 1 inchesof H2O). If the performance of the gas pressureregulator is erratic, the gas pressure regulator mayrequire service.

Natural Gas

Set the pressure of the fuel supply to a maximum of1 to 1.2 kPa (4 to 4.5 inches of H2O) HIGHER thanthe ambient air pressure.

Propane

Set the pressure of the fuel supply to−0.37 ± −0.06 kPa (−1.5 ±0.250 inches of H2O)LOWER than the ambient air pressure.

Note: If the engine is equipped with avaporizer/regulator for liquid propane fuelsupply, the vaporizer/regulator will regulate the fuelsupply pressure at the correct level. No adjustmentis required.

i01730803

Generator - DrySMCS Code: 4450-569

Personal injury or death can result from impropertroubleshooting and repair procedures.

The following troubleshooting and repair proce-dures should only be performed by qualified per-sonnel familiar with this equipment.

Refer to Safety Section, “Generator Isolating forMaintenance” for information regarding the procedureto safely isolate the generator.

If the insulation resistance values are less than therecommended values, one of the following dryingprocedures must be selected. This decision shouldbe based on the following factors:

• the size of the unit

• the location of the unit

• the equipment that is available

• the experience of personnel

Note: For more information on drying methods, referto Special Instruction, SEHS9124, “Cleaning andDrying of Electric Set Generators”.

Remove the voltage regulator. Cover all of the inletopenings. Cover all of the discharge holes. Providean opening at the top of the machine. This openingwill allow moisture to evaporate. Preferably, thisopening will be located at the fan end. Monitor thewinding temperatures. DO NOT APPLY HEAT TOORAPIDLY. Winding temperature should be raisedgradually at a rate of 10 °C (50 °F) per hour up to85 °C (185 °F). Measure insulation resistance at onehour intervals. Typically, the insulation resistancewill slowly drop while the temperature is rising. Theinsulation resistance will then start to increase at aslow rate until the insulation resistance reaches aconstant level.

The following methods can be used for drying agenerator:

• Self-circulating air method

• Oven method

• Controlled current method

Self-Circulating Air MethodDisconnect the generator load and run the engine.This will help circulate air.

Oven MethodPlace the entire generator inside a forced air dryingoven for four hours at 65 °C (149 °F).

NOTICEUse a forced air type oven rather than a radiant typeoven.

Radiant type ovens can cause localized overheating.

Controlled Current MethodTable 25

Tools Needed

PartNumber

Description Qty

8T-0900 Clamp on ammeter (1200amperes)

1

External Power Source 1

Rheostat 1


Generator Load - Check

Heat can be used in order to dry the generatorwindings. This heat can be created by allowing acontrolled current to flow through the generator. Nohigh voltages are generated during the followingprocedure. Therefore, insulation breakdown will notoccur.


Generator Wiring Diagram

(CR1-CR6) Diodes(CR7) Varistor(L1) Exciter field (stator)(L2) Exciter armature (rotor)(L3) Main field (rotor)(L4) Main armature (stator)(L5) Pilot exciter armature(PM) Permanent magnet(RFA) Rotating field assembly(CST) Customer supplied transformer

1. Make an external power source.

2. Refer to the above diagram. Disconnect “F1+”from the voltage regulator. Disconnect “F2-” fromthe voltage regulator. Disconnect the generatorload. Connect the generator output leads “T0”,“T1”, “T2”, and “T3”. Install the clamp-on ammeterto generator output lead “T1”.

Note: When the line current is measured onmultiple-lead units, measure the current in eachconductor per phase. The currents can then beadded.

3. Refer to the above diagram. Connect the rheostat.Adjust the rheostat to the maximum resistancevalue. Connect the external power source to wires“F1+” and “F2-”.

4. Start the generator set. Run the generator set atidle speed.

5. Monitor the phase current. Gradually increase theengine RPM. Increase the engine RPM until oneof the following conditions are met:

• The rated phase current is obtained.

• The full generator set speed is obtained.

6. If more phase current is still necessary, slowlyturn the rheostat until the rated phase current isreached.

7. On an hourly basis, stop the drying procedure.Check the insulation resistance. Repeat the abovesteps until the insulation resistance is acceptable.

i01473721

Generator Load - CheckSMCS Code: 4450-535-LA

During normal operation, monitor the power factorand monitor generator loading.

When a generator is installed or when a generatoris reconnected, ensure that the total current in anyone phase does not exceed the nameplate rating.Each phase should carry the same load. This allowsthe generator to work at the rated capacity. If onephase current exceeds the nameplate amperage,an electrical imbalance will occur. An electricalimbalance can result in an electrical overload and anelectrical imbalance can result in overheating.

The power factor can be referred to as the efficiencyof the load. This can be expressed as the ratio of kVAto actual kW. The power factor can be calculated bydividing kW by kVA. Power factor is expressed as adecimal. Power factor is used to mean the portionof current that is supplied to a system that is doinguseful work. The portion of the current that is notdoing useful work is absorbed in maintaining themagnetic field in motors. This current (reactive load)can be maintained without engine power.

Electric sets normally have a low idle setting thatis higher than industrial engines. Low idle will beapproximately 66 percent of the full speed that isachieved by 60 Hz units. This would be equal to 80percent of the full speed that is achieved by 50 Hzunits.

106 SEBU6682-08Maintenance SectionGenerator Set - Test

Some electric sets are equipped with Woodwardgovernors and some electric sets are equippedwith Caterpillar electronic governors. These electricsets have no low idle stop. On electric sets withmechanical governors and natural gas electric sets,the low idle is set at the factory. Adjustment of thelow idle on these machines should only be done bya Caterpillar dealer.

Note: Operating the electric set at low idle speed foran extended time will cause some voltage regulatorsto shut off. The electric set must be completely shutdown and the electric set must be restarted. Thiswill allow the voltage regulator to again produce anoutput.

i01473730

Generator Set - TestSMCS Code: 4450-081

Personal injury or death can result from high volt-age.

When power generation equipment must be in op-eration to make tests and/or adjustments, highvoltage and current are present.

Improper test equipment can fail and present ahigh voltage shock hazard to its user.

Make sure the testing equipment is designed forand correctly operated for high voltage and cur-rent tests being made.

When servicing or repairing electric power gener-ation equipment:

• Make sure the unit is off-line (disconnectedfrom utility and/or other generators powerservice), and either locked out or tagged DONOT OPERATE.

• Make sure the generator engine is stopped.

• Make sure all batteries are disconnected.

• Make sure all capacitors are discharged.

Table 26

Tools Needed

Part Number Part Quantity

6V-7070 DigitalMultimeter 1

12 VDC battery 1

PotentialTransformer 1

The generator set functional test is a simplified testthat can be performed in order to determine if thegenerator is functional. The generator set functionaltest should be performed on a generator set that isunder load.

The generator set functional test determines if thefollowing statements happen:

• A phase voltage is being generated.

• The phase voltages are balanced.

• The phase voltages change relative to enginespeed.

The generator set functional test consists of thefollowing steps:

1. Stop the generator. Connect the potentialtransformer’s high voltage winding to thegenerator terminals (T1) and (T2). Connectthe voltmeter to the low voltage winding. If twotransformers are available, connect the highvoltage winding of the second transformer to thegenerator terminals (T1) and (T3). Connect thesecondary terminals that correspond to generatorterminal (T2) of both transformers together.

2. Disconnect wires “F1+” and “F2-” from the voltageregulator. Disconnect the generator from the load.

3. Connect a 12 VDC automotive battery to wires“F1+” and “F2-”.

NOTICEDo not operate the generator set at a speed that ishigher than one-half of the rated speed.

Higher speeds under these test conditions can causedamage to the system.

4. Operate the generator set at half the rated speed.

5. Measure the AC voltage across the low voltageterminals of the transformer that correspond to thefollowing generator terminals: “T1” and “T2”, “T2”and “T3”, and “T3” and “T1”. Record the voltages.


Generator Set Vibration - Inspect

6. Monitor the voltage between any two of thelocations in step 5. Decrease the generator setspeed by 10 percent. Increase the generator setspeed by 10 percent.

7. The voltages that were measured in Step 5 shouldbe nearly equal. These voltages should measurea minimum of 85 VAC.

8. When the generator set speed is decreased by10 percent, the voltages that were measured inStep 6 should decrease by 10 percent. When thegenerator set speed is increased by 10 percent,the voltages that were measured in Step 6 shouldincrease by 10 percent.

i02211917

Generator Set Vibration -InspectSMCS Code: 4450-040-VI

Check for vibration damage. Vibration may cause thefollowing problems:

• Loose fittings

• Loose belts

• Excessive noise

• Cracked insulation

The following areas are susceptible to vibrationdamage:

• Stator output leads

• Protective sleeving

• Insulation

• Exposed electrical connections

• Transformers

• Fuses

• Capacitors

• Lightning arresters

When a generator set is installed a vibration plotshould be recorded in order to assist in diagnosingpotential problems. This vibration plot should beupdated yearly. The vibration plot should also beupdated when the generator set is moved. Refer toData Sheet, LEKQ4023, “Linear Vibration” for theallowable limits of vibration.

Contact the Caterpillar Dealer Service Tools groupfor information on ordering a vibration analyzer thatwill meet your needs.

i01041704

Governor - InspectSMCS Code: 1264-040

Inspect the governor for oil leaks.

For service information, see the literature that isprovided by the OEM of the governor.

i02523792

Hoses and Clamps - ReplaceSMCS Code: 1380-510

Note: For instructions on draining the cooling systemand filling the cooling system, see this Operationand Maintenance Manual, “Cooling System Coolant(NGEC) - Change” topic.

1. Drain the cooling system.

2. Remove the used hoses and clamps. Discard theitems.

3. Install new hoses and clamps. For thecorrect torque to use on the hose clamps,see the Specifications, SENR3130, “TorqueSpecifications”, “Hose Clamps” topic.

4. Fill the cooling system.

5. Start the engine. Inspect the hose connectionsfor leaks.

i01042052

Ignition System Spark PlugWires - Replace(Standard Ignition Systems)SMCS Code: 1558-510

Ignition systems can cause electrical shocks.Avoid contacting the ignition system componentsand wiring during operation.

108 SEBU6682-08Maintenance SectionIgnition System Spark Plugs - Check/Adjust/Replace

NOTICEPulling on the wiring harness may break the wires. Donot pull on the wiring harness.

1. Disconnect the spark plug wire assembly from thetransformer.

2. Disconnect the wire assembly from the spark plug.Discard the wire assembly.

3. Connect the new wire assembly to the spark plug.

4. Connect the wire assembly to the transformer.

i01617983

Ignition System Spark Plugs -Check/Adjust/ReplaceSMCS Code: 1555-535

There is a strong electrical shock hazard when thecrankshaft is rotating.

Do not touch the wires that are associated withthe ignition system when the engine is crankingor when the engine is running.

Maintenance of the spark plugs is required in orderto achieve the following benefits:

• Normal fuel consumption

• Normal level of emissions

• Maximum service life of the spark plugs

The service life of the spark plugs is affected byfouling due to deposits from the oil and by peakvoltage. Maintenance of the ignition system is alsoaffected by voltage. Higher voltage is required byhigher inlet manifold air pressure and a highercompression ratio. Higher voltage reduces theservice life of components such as spark plugs,wires, and transformers.

Removing the Spark Plug

Altronic Ignition System

Note: The Altronic ignition system has a transformerwhich is mounted separately from the spark plug.

g00837559Illustration 87(1) Wire for the secondary circuit(2) Transformer assembly(3) Boot(4) Seal(5) Spark plug

NOTICEPulling on the wiring harness may break the wires. Donot pull on the wiring harness.

1. Disconnect wire (1) from transformer assembly(2). The wire may break if you pull on the wire.

2. Remove boot (3) and the extension.

Pressurized air can cause personal injury. Whenpressurized air is used for cleaning, wear a pro-tective face shield, protective clothing, and pro-tective shoes.

3. Ensure that the area around the spark plug isclean and free of dirt and debris. Thoroughlyremove any debris. Use compressed air. Themaximum air pressure for cleaning purposes mustbe below 207 kPa (30 psi). A nonmetallic brushcan also be used.

4. Use a deep well socket with an extension in orderto remove spark plug (5). After the spark plug hasbeen loosened, remove the spark plug by hand inorder to detect problems with the threads. Afterthe spark plug has been removed, discard theused spark plug gasket.


Ignition System Spark Plugs - Check/Adjust/Replace

If the spark plug resists removal by hand, applypenetrating oil to the threads. To help the oil penetratethe threads, use the wrench and turn the spark plugback and forth until the spark plug is loose.

NOTICEDo not use a thread tap. A thread tap will removemetalunnecessarily. The threads could be stripped and thespark plug adapter could be damaged.

If the spark plug cannot be removed by hand, cleanthe internal threads with the 9U-7511 Spark PlugSeat Cleaner. This tool scrapes debris from the seatand from the threads in the cylinder head. Be sure toclean any debris from the cylinder.

CSA Ignition System (Altronic)

Note: The CSA ignition system is equipped with anintegral transformer. The transformer screws onto thespark plug. The transformer and the spark plug areremoved separately. The transformer and the sparkplug are installed separately.


(1) Wiring harness(2) Boot(3) Transformer(4) Spacer(5) Spark plug

1. Unscrew wiring harness (1) from the threadedconnector.

2. Remove boot (2).

3. Unscrew transformer (3) from spark plug (5) inorder to remove the transformer.

Pressurized air can cause personal injury. Whenpressurized air is used for cleaning, wear a pro-tective face shield, protective clothing, and pro-tective shoes.

4. Ensure that the area around the spark plug isclean and free of dirt and debris. Thoroughlyremove any debris. Use compressed air. Themaximum air pressure for cleaning purposes mustbe below 207 kPa (30 psi). A nonmetallic brushcan also be used.

5. Use a deep well socket with an extension in orderto remove spark plug (5). After the spark plug hasbeen loosened, remove the spark plug by hand inorder to detect problems with the threads. Afterthe spark plug has been removed, discard theused spark plug gasket.

Note: Ensure that you keep copper spacer (4) that isinstalled between the end of the transformer and thetop of the hex on the spark plug.

If the spark plug resists removal by hand, applypenetrating oil to the threads. To help the oil penetratethe threads, use the wrench and turn the spark plugback and forth until the spark plug is loose.

NOTICEDo not use a thread tap. A thread tap will removemetalunnecessarily. The threads could be stripped and thespark plug adapter could be damaged.

If the spark plug cannot be removed by hand, cleanthe internal threads with the 9U-7511 Spark PlugSeat Cleaner. This tool scrapes debris from the seatand from the threads in the cylinder head. Be sure toclean any debris from the cylinder.

Fairbanks Morse Ignition System

Note: The Fairbanks Morse ignition system has anintegral transformer that screws directly onto thespark plug. The transformer and the spark plug areremoved as an assembly.


g00837582Illustration 89(1) Wiring harness(2) Boot(3) Transformer(4) Spark plug(5) Spacer

1. Disconnect wiring harness (1).

2. Remove boot (2).

3. Remove transformer (3) and spark plug (4) as aunit.

4. Remove the spark plug from the transformer.

Note: Ensure that you keep copper spacer (5) that isinstalled between the end of the transformer and thetop of the hex on the spark plug.

Inspecting the Spark PlugNote: Some spark plugs have electrodes witha single ground strap. Some spark plugs haveelectrodes with two ground straps.

g00830138Illustration 90Typical spark plug with a single ground strap(1) Terminal post(2) Insulator(3) Shell(4) Gasket(5) Electrode

g00829527Illustration 91Section view and bottom view of a spark plug with two groundstraps

Inspect the spark plug closely for damage. Thecondition of the spark plug can indicate the operatingcondition of the engine.

Inspect insulator (2) for cracks. If a crack is found,discard the spark plug.

Faint marks may extend from shell (3) onto theinsulator. The marks may be a result of a coronathat forms at the top of the shell. The conductor willdevelop a corona when a very high voltage potentialionizes the air. This is a normal condition. This is notan indication of leakage between the shell and theinsulator.

Inspect shell (3) for damage. Cracks can be causedby overtightening the spark plug. Overtightening canalso loosen the shell. Discard any spark plug that hasa shell that is cracked or loose.

Caterpillar spark plugs have precious metal tips onthe ends of the electrodes. This material will graduallyerode. Use extreme care when you set the electrodegap. Maintain even spacing and proper alignmentbetween the precious metal surfaces.

Replace the spark plug if the precious metal is wornoff.


Ignition System Spark Plugs - Check/Adjust/Replace

A light brown deposit or a beige deposit is producedby normal operation.

Deposits that are gray or black may be caused bythe following substances:

• Excessive oil

• Use of the wrong oil

• A substance that is introduced through the fuelsystem or the air system

A spark plug can operate despite a buildup of ash.However, a buildup of ash can cover the electrodegap. This will cause misfire. Large deposits mayretain heat which can cause premature fuel ignition.This can lead to uncontrollable detonation.

Cleaning the Spark PlugThoroughly clean the spark plug. Do not use a wirebrush. Glass beads are the preferred method forcleaning.

Follow these guidelines for using glass beads:

• Always use clean glass beads.

• Use care in order to clean only the electrode andthe insulator near the electrode.

• Do not use glass beads on the outside of the shellor on the upper part of the insulator.

Checking the Spark PlugAfter the spark plug is clean, measure the sparkplug’s electrode gap.

Note: Use the 9U-7516 Spark Plug Gauge tomeasure the electrode gap. Do not use a flat feelergauge for measuring the electrode gap of used sparkplugs. A feeler gauge will incorrectly measure theactual electrode gap because the used preciousmetal tips are curved.

Adjust the electrode gap by bending the groundelectrode at the existing bend. Then bend the strapnear the weld in order to achieve proper alignmentand even spacing between the two precious metalsurfaces. Measure the electrode gap after thealignment. Correct the electrode gap, if necessary.

For low emission engines, adjust the electrode gapto 0.28 mm (0.011 inch).

For stoichiometric engines, adjust the spark plug gapto 0.38 mm (0.015 inch).

Installing the Spark PlugNote: Do not use anti-seize compound on sparkplugs. Most of the heat is transferred through thethreads and the seat area of the spark plug. Thesurfaces must be in contact in order to provide theheat transfer that is required.

Ensure that the spark plug is clean and free of dirtand oil.

Always use a new gasket when a spark plug isinstalled. Orient the tabs of the gasket toward thecombustion chamber. Otherwise, the gasket may notseat properly. If a gasket for a spark plug is installedincorrectly, do not increase the torque on the sparkplug in order to improve the seal. Do not reuse thegasket. Install a new gasket.

Altronic Ignition System


(1) Wire for the secondary circuit(2) Transformer assembly(3) Boot(4) Seal(5) Spark plug

NOTICEDo not overtighten the spark plug. The shell can becracked and the gasket can be deformed. The met-al can deform and the gasket can be damaged. Theshell can be stretched. This will loosen the seal that isbetween the shell and the insulator, allowing combus-tion pressure to blow past the seal. Serious damageto the engine can occur.

Use the proper torque.


1. Install spark plug (5) by hand until the spark plugbottoms out.

For spark plugs with a single ground strap, tightenthe spark plug to 30 ± 4 N·m (22 ± 3 lb ft).

For spark plugs with two ground straps, tightenthe spark plug to 25 ± 5 N·m (18 ± 4 lb ft).

2. Inspect seal (4), boot (3), and wire (1). If thecomponents are in good condition, install thecomponents. If the components are not in goodcondition, install new components.

CSA Ignition System

g00798357Illustration 93(1) Wiring harness(2) Boot(3) Transformer(4) Spacer(5) Spark plug

1. Place spacer (4) on top of the spark plug’s hex.Install spark plug (5) by hand until the spark plugbottoms out.



2. Screw transformer (3) onto spark plug (5) untilthe transformer is finger tight. Then tighten thetransformer for an additional one-eighth turn (45degrees).

3. Inspect boot (2) and wiring harness (1). If thecomponents are in good condition, install thecomponents. If a component is not in goodcondition, replace the old component with a newcomponent.

Fairbanks Morse Ignition System

g00837582Illustration 94(1) Wiring harness(2) Boot(3) Transformer(4) Spark plug(5) Spacer

1. Place spacer (5) on top of the spark plug’s hex.Install spark plug (4) into transformer (3). Tightenthe spark plug to 47 ± 3 N·m (35 ± 2 lb ft).

2. Install spark plug (4) and transformer (3) as a unit.



3. Inspect boot (2) and wiring harness(1). If thecomponents are in good condition, install thecomponents. If a component is not in goodcondition, replace the old component with a newcomponent.


Ignition System Timing - Check/Adjust

i01005974

Ignition System Timing -Check/AdjustSMCS Code: 1550-025; 1550-535

After maintenance has been performed on theignition system, check the timing of the ignitionsystem. Adjust the timing, if necessary.

The optimum ignition timing for a gas engine variesaccording to several factors:

• Compression ratio of the engine

• Inlet air temperature

• Methane number of the gas

For the proper timing, see the Engine Performancepublication for the engine.

Adjust the timing according to the Service Manual,“Systems Operation/Testing and Adjusting” module.Consult your Caterpillar dealer for assistance.

i00682407

Ignition System TransformerResistance - TestSMCS Code: 1550-081

The transformers produce a voltage increase. Forgood operation, the connections must be clean andsecure. Inspect the transformers for the followingconditions. If any of the conditions are found, correctthe condition:

• Corrosion

• Dirty insulator


• Moisture

• Open circuits

• Short circuits

Test the resistance of the transformers. Test eachtransformer at both the side with high voltage andthe side with low voltage. See the Service Manual,“Specifications” module for the procedure. Consultyour Caterpillar dealer for assistance.

i01113853

Inlet Air System - InspectSMCS Code: 1058-040; 1071-040; 1087-040

Inspect the components of the air inlet system forthe following conditions:

• Cracks

• Leaks


Inspect the following components:

• Piping between the air cleaner and the turbocharger

• Turbocharger

• Piping between the turbocharger and theaftercooler

• Aftercooler

• Connection of the aftercooler to the air plenum

• Connection of the air plenum to the cylinder head

Ensure that all of the connections are secure. Ensurethat the components are in good condition.

Make repairs, if necessary. For information regardingremoval and installation of the components, seethe Service Manual, “Disassembly and Assembly”module. Consult your Caterpillar dealer forassistance.

i01021379

Instrument Panel - InspectSMCS Code: 7451-040

Inspect the instrument panel for good condition.Check the condition of all of the gauges. If a gaugeis broken, repair the gauge or replace the gaugeimmediately.

Frequently monitor the following parameters duringnormal operation:

• Fuel filter differential pressure

• Inlet air restriction

• Inlet manifold air temperature

• Jacket water temperature

114 SEBU6682-08Maintenance SectionInsulation - Test

• Oil filter differential pressure

• Oil pressure

Record the data in a log. Compare the new data tothe data that was previously recorded. Comparingthe new data to the recorded data will establish thenormal gauge readings for the engine. A gaugereading that is abnormal may indicate a problem withoperation or a problem with the gauge.

i01494696

Insulation - TestSMCS Code: 4453-081; 4454-081; 4457-081;4470-081

Recommended Periodic InsulationTests

The high voltage that is produced by an operatinggenerator set can cause severe injury or death.Before performing any maintenance or repairs,ensure that the generator will not start.

Place the engine control switch in the “OFF” posi-tion. Attach “DO NOT OPERATE” tags to all start-ing controls. Disconnect the batteries or disablethe starting system. Lock out all switchgear andautomatic transfer switches that are associatedwith the generator.

Table 27

Tools Needed

Part Number Part Name Quantity

142-5055 InsulationTesting Gp

1

9U-6003 InsulationTesting Gp

1

Periodically, use an insulation tester to check theinsulation resistance of the generator’s main statorwinding. The frequency of this test is determined bythe generator’s environment. Previous insulationtester readings will also determine the frequency ofthis test.

Test the main stator windings with an insulation testerin the following situations:

• The generator set is started for the first time.

• The generator set is removed from storage.

• The generator set is operating in a humidenvironment. Test every three months.

• The generator set is not protected from theelements in an enclosed area. Test every threemonths.

• The generator set is installed in an enclosed area.This area needs to be low in humidity and this areaneeds to have steady temperatures. Test everytwelve months (minimum).

• The generator set has not been run under loadfor three months. Test the generator set weekly.Use space heaters around the generator set if thegenerator is exposed to a sea water environment orif the humidity is above 75 percent. Also use spaceheaters if a test result was below 3 megohms.

Space heaters must be used whenever the generatorset is not under load. Space heaters must also beused whenever salt is present or whenever highhumidity is present. Using a space heater in thisfashion is the only way to maintain insulation testerreadings above one megohm. Use space heatersonly when the generator is not running.

For additional information, refer to Special Instruction,SEHS9124, “Cleaning and Drying of Electric SetGenerators”.

Recommended Periodic InsulationTest Procedure

Personal injury or death can result from electro-cution.

The megohmmeter is applying a high voltage tothe circuit.

To avoid electrocution, do not touch the instru-ment leads without first discharging them. Whenfinished testing also discharge the generatorwindings.

1. Take the generator out of service.

2. Visually inspect the generator for moisture. Ifmoisture exists, do not perform this insulationtest. Dry the unit first. Refer to Special Instruction,SEHS9124, “Cleaning and Drying of Electric SetGenerators”.

3. Inspect the installation. Determine the equipmentthat will be tested by the insulation tester.

4. Discharge the capacitance of the windings.


Insulation - Test

5. Disconnect “T0” from ground.

6. Disconnect the regulator sensing lead wires: “20”,“22”, and “24”.

7. Connect the insulation tester’s RED lead toground.

8. Connect the insulation tester’s BLACK lead to“T0”.

9. For units that are 600 volts or less, set the voltageto 500 Volts. For units that are more than 600volts, set the voltage to 1000 Volts.

10.Use the 30/60 Time Resistance Method:

a. Apply voltage.

b. Observe the readings at 30 seconds. Observethe readings at 60 seconds.

c. Record the 60 second reading. This readingmust be corrected for temperature.

d. Record temperature.

e. Record humidity.

f. Remove voltage.

11.Evaluate the readings. The actual value of theresistance may vary greatly between generators.For this reason, the insulation’s condition must beevaluated. Base this evaluation on the comparisonbetween the 60 second resistance readings andthe readings that were taken on previous dates.These two readings must be taken under similarconditions. If a 60 second resistance readinghas a 50 percent reduction from the previousreading, the insulation may have absorbed toomuch moisture.

Switch the insulation tester to the “OFF” position.This will discharge the insulation tester’s leads.Disconnect the insulation tester’s leads.

Note: The results from the insulation resistancechecks indicate when cleaning and/or repairing isbecoming critical. Generally, insulation resistancewill vary greatly with temperature. Therefore, alwaystest at the same temperature and humidity. Refer toIllustration 95.

Engine Serial Number_____________________________________

Generator Serial Number_________________________________

116 SEBU6682-08Maintenance SectionInsulation - Test



Jacket Water Heater - Check

i01042517

Jacket Water Heater - CheckSMCS Code: 1383-535

Jacket water heaters help to improve startability inambient temperatures that are below 21 °C (70 °F).All installations that require automatic starting shouldhave jacket water heaters.

Check the operation of the jacket water heater. Foran ambient temperature of 0 °C (32 °F), the heatershould maintain the jacket water temperature atapproximately 32 °C (90 °F).

i02064343

Overhaul (Major)SMCS Code: 7595-020-MJ

Scheduling a Major OverhaulThe need for a major overhaul is determined byseveral factors.

• An increase of oil consumption

• An increase of crankcase blowby

• A decrease and variation of cylinder compression

The following changes in the three conditionsnormally require a scheduled overhaul:

• A 300 percent increase in oil consumption

• A 200 percent increase in crankcase blowby

• A 20 percent loss of cylinder compression

Note: These indications do not require an engineto be shut down for service. These indicationsonly mean that an engine should be scheduled forservice in the near future. If the engine operationis satisfactory, an immediate overhaul is not arequirement.

The engine does not require an overhaul if theengine is operating within acceptable limits foroil consumption, crankcase blowby, and cylindercompression.

Other factors must also be considered for determininga major overhaul:

• The service hours of the engine

• The wear metal analysis of the lube oil

• An increase in the levels of noise and vibration

An increase of wear metals in the lube oil indicatesthat the bearings and the surfaces that wear mayneed to be serviced. An increase in the levels ofnoise and vibration indicates that rotating partsrequire service.

Note: It is possible for oil analysis to indicate adecrease of wear metals in the lube oil. The cylinderliners may be worn so that polishing of the boreoccurs. Also, the increased use of lube oil will dilutethe wear metals.

Monitor the engine as the engine accumulatesservice hours. Consult your Caterpillar dealer aboutscheduling a major overhaul.

Note: The driven equipment may also require servicewhen the engine is overhauled. Refer to the literaturethat is provided by the OEM of the driven equipment.

Major Overhaul InformationA major overhaul includes all of the work that is donefor top end overhauls. A major overhaul includesadditional parts and labor. Additional parts andlabor are required in order to completely rebuild theengine. In some cases, the engine is relocated fordisassembly.

For the major overhaul, all of the bearings,seals, gaskets, and components that wear aredisassembled. The parts are cleaned and the partsare inspected. If necessary, the parts are replaced.The crankshaft is measured for wear. The crankshaftmay require regrinding. Alternatively, the crankshaftmay be replaced with a Caterpillar replacement part.

Your Caterpillar dealer can provide these servicesand components. Your Caterpillar dealer can ensurethat the components are operating within theappropriate specifications.

If you elect to perform an overhaul without theservices of a Caterpillar dealer, be aware of thefollowing recommendations.

The following definitions explain the terminology forthe services that are performed during an overhaul:

118 SEBU6682-08Maintenance SectionOverhaul (Major)

Inspect – Inspect the components according tothe instructions that are in Caterpillar reusabilitypublications. Refer to Guidelines for ReusableParts and Salvage Operations, SEBF8029, “Indexof Publications on Reusability or Salvage of UsedParts”. The guidelines were developed in order tohelp Caterpillar dealers and customers to avoidunnecessary expenditures. New parts are notrequired if the existing parts can still be used,reconditioned, or repaired. If the components arenot in the reusability guidelines, refer to the ServiceManual, “Specifications” module.

Rebuild – The component can be reconditioned inorder to comply with reusability guidelines.

Replace – The service life of the part is exhausted.The part may fail before the next maintenanceinterval. The part must be replaced with a part thatmeets functional specifications. The replacementpart may be a new part, a CAT remanufactured part,a rebuilt part, or a used part. Some worn componentsmay be exchanged with your Caterpillar dealer.Consult your Caterpillar dealer about repair optionsfor your engine.

Replacing of Components

Note: The cylinder head may be rebuilt, whenpossible.

Replace the following components during the majoroverhaul.

• Alternator

• Alternator and fan drive belts

• Camshaft bearings

• Connecting rod bearings

• Crankshaft bearings

• Crankshaft seals

• Crankshaft vibration damper

• Cylinder liners

• Cylinder head and gaskets

• Exhaust manifold

• Gaskets and seals

• Gear train bearings

• Governor

• Hoses and clamps

• Main bearings

• Piston rings

• Rod ends for the control linkage of the actuator

• Spark plugs

• Spark plug wires

• Transformers

• Valve rotators

• Water temperature regulators

• Wiring harnesses

Rebuilding of Components

Rebuild the following components during the majoroverhaul. If the components cannot be rebuilt,replace the components.

• Carburetor

• Cylinder packs

• Exhaust bypass

• Gas regulator

• Inlet air piping

• Oil pump

• Starting motor

• Turbocharger

• Water pumps

Inspecting Components

Inspect the following components according tothe instructions that are in Caterpillar reusabilitypublications. Refer to Guidelines for ReusableParts and Salvage Operations, SEBF8029, “Indexof Publications on Reusability or Salvage of UsedParts”.

• Aftercooler

• Camshafts

• Camshaft followers

• Connecting rods

• Crankshaft

SEBU6682-08 119Maintenance SectionOverhaul (Top End)

• Gears of the gear train

• Gear train bushings

• Governor

• Inlet air piping

• Oil cooler

• Oil pump

• Pistons

• Transformers

i02064373

Overhaul (Top End)SMCS Code: 7595-020-TE

Scheduling a Top End OverhaulTop end overhauls are scheduled according tothe recession of the exhaust valve stems. Thismeasurement provides an accurate indication of therate of valve wear. This measurement can be used topredict when a cylinder head requires replacement.For more information, refer to this Operation andMaintenance Manual, “Valve Stem Projection -Measure/Record” topic.

Note: The generator or the driven equipment mayalso require service when the engine overhaul isperformed.

Top End Overhaul InformationA top end overhaul involves servicing the cylinderheads and turbochargers. Also, some other enginecomponents are inspected.

Top end overhauls require more tools than preventivemaintenance. The following tools are needed forrestoring the engine to factory specifications:

• Torque wrenches

• Dial indicators

• Accurate measurement tools

• Cleaning equipment

• Rebuilding equipment

Caterpillar dealers are equipped with these tools.Caterpillar dealers can provide a flat rate price fora top end overhaul.

Unexpected problems may be found during a topend overhaul. Plan to correct these problems, ifnecessary.

• Buildup in the cylinders from excessive oilconsumption

• Buildup in the cylinders from contamination of thefuel

• Plugging of the aftercooler from coolant that ispoorly maintained

• Plugging of the aftercooler from contamination ofthe inlet air

• Degradation of the oil cooler from hydrogen sulfidein the fuel

Inspect the following components according tothe instructions that are in Caterpillar reusabilitypublications. Refer to Guidelines for ReusableParts and Salvage Operations, SEBF8029, “Indexof Publications on Reusability or Salvage of UsedParts”.

Your Caterpillar dealer can provide these servicesand components. Your Caterpillar dealer can ensurethat the components are operating within theappropriate specifications.

If you elect to perform an overhaul without theservices of a Caterpillar dealer, be aware of thefollowing recommendations.

The following definitions explain the terminology forthe services that are performed during an overhaul:

Inspect – Inspect the components according tothe instructions that are in Caterpillar reusabilitypublications. Refer to Guidelines for ReusableParts and Salvage Operations, SEBF8029, “Indexof Publications on Reusability or Salvage of UsedParts”. The guidelines were developed in order tohelp Caterpillar dealers and customers to avoidunnecessary expenditures. New parts are notrequired if the existing parts can still be used,reconditioned, or repaired. If the components arenot in the reusability guidelines, refer to the ServiceManual, “Specifications” module.

Rebuild – The component can be reconditioned inorder to comply with reusability guidelines.

120 SEBU6682-08Maintenance SectionOverhaul (Top End)

Replace – The service life of the part is exhausted.The part may fail before the next maintenanceinterval. The part must be replaced with a part thatmeets functional specifications. The replacementpart may be a new part, a CAT remanufactured part,a rebuilt part, or a used part. Some worn componentsmay be exchanged with your Caterpillar dealer.Consult your Caterpillar dealer about repair optionsfor your engine.

Replacing of Components

Note: The cylinder head may be rebuilt, whenpossible.

Replace the following components during a top endoverhaul.

• Alternator and fan drive belts

• Cylinder heads and gaskets

• Forward bearing of the fan drive

• Hoses and clamps

• Rod ends for the control linkage of the actuator

• Spark plugs

• Spark plug wires

• Water temperature regulator

Rebuilding of Components

Rebuild the following components during a top endoverhaul:

• Carburetor

• Gas regulator

• Starting motor

• Turbocharger

• Water pumps

Note: Periodic inspection of the turbocharger isrecommended for determining when the turbochargerwill require an overhaul. In a few applications, theturbocharger may require rebuilding prior to the topend overhaul. An example is an application withloads that vary frequently. In these cases, rebuildingthe turbocharger normally occurs separately fromrebuilding the cylinder heads. Some applicationscan operate longer before the turbocharger requiresrebuilding. Only experience can determine the actualneed.

Inspecting of Components

Clean the following components. Pressure test thecomponents. Replace the components, if necessary:

• Aftercooler core (if equipped)

• Oil cooler core

Note: It is difficult to clean the aftercooler core whenmaintenance is not performed.

Note: This procedure may be used for cleaning boththe aftercooler core and the oil cooler core.

1. Remove the core. For the procedure, refer to theService Manual, “Disassembly and Assembly”module.

2. Turn the core upside-down in order to removedebris.

NOTICEDo not use a high concentration of caustic cleaner toclean the core. A high concentration of caustic cleanercan attack the internal metals of the core and causeleakage. Only use the recommended concentration ofcleaner.

NOTICEDo not use a high pressure spray for cleaning the finsof the core. A high pressure spray can damage thesurface of the fins and reduce the flow of air throughthe core.

3. Back flush the core with cleaner.

Caterpillar recommends the use of Hydrosolvliquid cleaner. Use a two to five percentconcentration of the cleaner at temperatures upto 93 °C (200 °F). Refer to Application Guide,NEHS0526 or consult your Caterpillar dealer formore information.

4. Steam clean the core in order to remove anyresidue. Flush the fins of the core. Remove anyother trapped debris.

5. Wash the core with hot, soapy water. Rinse thecore thoroughly with clean water.


Overhaul Considerations




6. Dry the core with compressed air. Direct the air inthe reverse direction of the normal flow.

Note: The test pressure for the oil cooler is 790 kPa(115 psi). The maximum differential pressure of waterfor the aftercooler is 44 kPa (6 psi). The maximumdifferential pressure of air for the aftercooler is5.1 kPa (0.74 psi).

7. Inspect the core in order to ensure cleanliness.Pressure test the core. Many shops that serviceradiators are equipped to perform pressure tests.If necessary, repair the core.

8. Install the core. For the procedure, refer to theService Manual, “Disassembly and Assembly”module.

For more information on cleaning the cores, consultyour Caterpillar dealer.

Exhaust Bypass

Inspect the condition of the exhaust bypass (ifequipped). Recondition the component, if necessary.Refer to this Operation and Maintenance Manual,“Exhaust Bypass - Inspect” topic (MaintenanceSection).

Governor

Inspect the governor for proper operation. Make anyrepairs that are necessary.

Transformers

The transformers produce a voltage increase. Forgood operation, the connections must be clean andsecure. Inspect the transformers for the followingconditions:

• Dirty insulator


• Loose connector

• Moisture

Test the resistance of the transformers according tothe Service Manual, “Specifications” module. Consultyour Caterpillar dealer for assistance.

i02049051

Overhaul ConsiderationsSMCS Code: 7595-043

Overhaul InformationAn overhaul is replacing the major worn componentsof the engine. An overhaul is a maintenance intervalthat is planned. The engine is rebuilt with certainrebuilt parts or new parts that replace the worn parts.

An overhaul also includes the following maintenance:

• Inspection of all the parts that are visible duringthe disassembly

• Replacement of the seals and gaskets that areremoved

• Cleaning of the internal passages of the engineand the engine block

Most owners will save money by overhauling theengine at the intervals that are recommended inthis Operation and Maintenance Manual. It is notpractical to wait until the engine exhibits symptomsof excessive wear or failure. It is not less costly towait. A planned overhaul before failure may be thebest value for the following reasons:

• Costly unplanned downtime can be avoided.

• Many original parts can be reused according to theguidelines for reusable parts.

• The service life of the engine can be extendedwithout the risk of a major catastrophe due toengine failure.

• Achieve the best cost/value relationship per hourof extended service life.

Overhaul Intervals

Top end overhauls are determined by the projection ofexhaust valve stems. Major overhauls are determinedby cylinder compression, crankcase blowby, oilconsumption, and results of S·O·S oil analysis.

Some other factors that are important for determiningthe overhaul intervals include the followingconsiderations:

• Performance of preventive maintenance

122 SEBU6682-08Maintenance SectionPower Factor - Check

• Use of recommended lubricants

• Use of recommended coolants

• Use of recommended fuels

• Proper installation

• Operating conditions

• Operation within acceptable limits

• Engine load

• Engine speed

Note: To avoid oil problems, engines that areturbocharged and aftercooled must be operated at aminimum of 60 percent of rated load.

Generally, engines that are operated at a reducedload and/or speed achieve more service life beforean overhaul. However, this is for engines that areproperly adjusted, operated and maintained.

Overhaul Inspection

Refer to the Service Manual for the disassembly andassembly procedures that are necessary in orderto perform the required maintenance on the itemsthat are listed. Consult your Caterpillar dealer forassistance.

To determine the reusability publications that areneeded to inspect the engine, refer to Guidelines forReusable Parts and Salvage Operations, SEBF8029,“Index of Publications on Reusability or Salvage ofUsed Parts”.

The Guidelines For Reusable Parts and SalvageOperations is part of an established Caterpillarparts reusability program. These guidelines weredeveloped in order to assist Caterpillar dealers andcustomers reduce costs by avoiding unnecessaryexpenditures for new parts. If the engine parts complywith the established inspection specifications, theparts can be reused. New parts are not necessary ifthe old parts can be reused, repaired, or salvaged.

If the parts are not within the inspection specifications,the parts should be salvaged, repaired, replaced,or exchanged. The use of out-of-spec parts couldresult in unscheduled downtime and/or costly repairs.The use of out-of-spec parts can also contribute toincreased fuel consumption and reduction of engineefficiency.

Your Caterpillar dealer can provide the parts that areneeded to rebuild the engine at the least possiblecost.

Overhaul Programs

An economical way to obtain most of the partsthat are needed for overhauls is to use Caterpillarremanufactured parts. Caterpillar remanufacturedparts are available at a fraction of the cost of newparts. These parts have been rebuilt by Caterpillarand certified for use. The following components areexamples of the remanufactured parts:

• Alternators

• Connecting rods

• Crankshafts

• Cylinder heads

• Oil Pumps

• Starting motors

• Turbochargers

• Water pumps

Consult your Caterpillar dealer for details and for alist of the remanufactured parts that are available.

Your Caterpillar dealer may be offering a variety ofoverhaul options.

A Flat Rate Overhaul guarantees the maximum pricethat you will pay for an overhaul. Flat rate prices onpreventive maintenance programs or major repairoptions are available from many servicing dealersfor all Caterpillar Engines. Consult your Caterpillardealer in order to schedule a before failure overhaul.

Overhaul Recommendation

Caterpillar recommends a scheduled overhaul inorder to minimize downtime. A scheduled overhaulwill provide the lowest cost and the greatest value.Schedule an overhaul with your Caterpillar dealer.

Overhaul programs vary between dealers. To obtainspecific information about the types of overhaulprograms and services, consult your Caterpillardealer.

i01216962

Power Factor - CheckSMCS Code: 4450-535-PWR

The power factor of a system can be determined bya power factor meter or by calculations. The powerfactor can be calculated by dividing kW by kVA.Power factor is expressed as a decimal.


Radiator - Clean

i01604510

Radiator - CleanSMCS Code: 1353-070

Note: Adjust the frequency of cleaning according tothe effects of the operating environment.

Inspect the radiator for these items: damaged fins,corrosion, dirt, grease, insects, leaves, oil, and otherdebris. Clean the radiator, if necessary.




Pressurized air is the preferred method for removingloose debris. Direct the air in the opposite directionof the fan’s air flow. Hold the nozzle approximately6 mm (0.25 inch) away from the fins. Slowly move theair nozzle in a direction that is parallel with the tubes.This will remove debris that is between the tubes.

Pressurized water may also be used for cleaning.The maximum water pressure for cleaning purposesmust be less than 275 kPa (40 psi). Use pressurizedwater in order to soften mud. Clean the core fromboth sides.

Use a degreaser and steam for removal of oil andgrease. Clean both sides of the core. Wash the corewith detergent and hot water. Thoroughly rinse thecore with clean water.

After cleaning, start the engine and accelerate theengine to high idle rpm. This will help in the removalof debris and drying of the core. Stop the engine.Use a light bulb behind the core in order to inspectthe core for cleanliness. Repeat the cleaning, ifnecessary.

Inspect the fins for damage. Bent fins may be openedwith a “comb”. Inspect these items for good condition:welds, mounting brackets, air lines, connections,clamps, and seals. Make repairs, if necessary.

For more detailed information on cleaning andinspection, refer to Special Publication, SEBD0518,“Know Your Cooling System”.

i01218154

Space Heater - CheckSMCS Code: 4450-535-HTR

An SR4B generator is capable of operating in highhumidity conditions without problems. However,problems can occur when the generator is idle andthe surrounding air is warmer than the generator.Moisture can form on the windings that will result inpoor performance from the windings. Moisture canalso result in damage to the windings. Whenever thegenerator is not active, ensure that the space heatersare in operation.

i01511915

Speed Sensor - Clean/InspectSMCS Code: 1907-040; 1907-070


Speed sensors

1. Remove the speed sensor from the flywheelhousing. Check the condition of the end ofthe magnet. Check for signs of wear andcontaminants.

2. Clean the metal shavings and other debris fromthe face of the magnet.

3. Install the speed sensor and adjust the speedsensor according to the engine’s Specificationsmodule.

124 SEBU6682-08Maintenance SectionStandby Generator Set Maintenance Recommendations

i01038735

Standby GeneratorSet MaintenanceRecommendationsSMCS Code: 4450-041

A standby generator set may not need to be usedvery often. However, the generator set is usuallyneeded for operation in an emergency situation.Maintenance of the standby generator set is veryimportant for the following reasons:

• The generator set must always be in excellentoperating condition.

• The generator set must be ready to work underload at any time.

Establishing a Preventive Maintenance Program willprovide these benefits:

• Maximum availability of the standby generator set

• Longer service life for the generator set

• Minimum of expensive repairs

Your Caterpillar dealer can help you to establish aneffective Preventive Maintenance Program for yourgenerator set. Consult your Caterpillar dealer fordetails.

Maintenance and OperationProcedures



The recommended maintenance for the engine islisted in this Operation and Maintenance Manual,“Maintenance Interval Schedule (Standby GeneratorSet Engines)” (Maintenance Section).

For the recommended generator maintenance, seethe Operation and Maintenance Manual for thegenerator and the control panel.

Maintenance and Repair

The maintenance that is recommended for EveryWeek can be performed by an authorized operator.The maintenance that is recommended for thesubsequent maintenance intervals must beperformed by an authorized service technician or byyour Caterpillar dealer.

Unless other instructions are provided, performmaintenance and repairs under the followingconditions:

• The engine is stopped.

• The starting system is disabled.

• The generator does not pose an electrical shockhazard.

Operation

To ensure proper operation, the generator set must beexercised regularly. For instructions on operating thegenerator set, see the Operation and MaintenanceManual for the generator set control panel.

For these operation procedures, follow theinstructions that are provided in this Operation andMaintenance Manual, “Operation Section”: startingthe engine, engine operation, and stopping theengine.

Record Keeping

Maintain a record in order to document these items:gauge readings, maintenance that is performed,problems, and repairs.

Space Heaters

Moisture causes damage to generators and otherelectrical equipment. Make every effort to keep thegenerator set as dry as possible.

Generators can operate without problems in humidenvironments. However, problems can occur whenthe generator is inactive. Moisture can condense onthe windings. This can result in poor performance.Also, damage to the windings can occur.

Use space heaters in order to help keep the windingsdry. When the generator is not active, ensure that thespace heaters are operating. When the generator isoperating, turn OFF the space heaters.


Starting Motor - Inspect

i01113939

Starting Motor - InspectSMCS Code: 1451-040; 1453-040

If the starting motor fails, the engine may not start inan emergency situation. A scheduled inspection ofthe starting motor is recommended.

The starting motor pinion and the flywheel ring gearmust be in good condition in order for the engineto start properly. The engine will not start if thestarting motor pinion does not engage the flywheelring gear. The teeth of the starting motor pinion andthe flywheel ring gear can be damaged because ofirregular engagement.

Inspect the starting motor for proper operation. Listenfor grinding when the engine is started. Inspect theteeth of the starting motor pinion and the flywheelring gear. Look for patterns of wear on the teeth. Lookfor teeth that are broken or chipped. If damaged teethare found, the starting motor pinion and the flywheelring gear must be replaced.

Electric Starting MotorNote: Problems with the electric starting motor canbe caused by the following conditions: malfunction ofthe solenoid and malfunction of the electric startingsystem.

Inspect the electrical system for the followingconditions:


• Corrosion

• Wires that are worn or frayed

• Cleanliness

Make repairs, if necessary.

Air Starting Motor

Personal injury or death can result from improp-erly checking for a leak.

Always use a board or cardboard when checkingfor a leak. Escaping air or fluid under pressure,even a pin-hole size leak, can penetrate body tis-sue causing serious injury, and possible death.

If fluid is injected into your skin, it must be treatedimmediately by a doctor familiar with this type ofinjury.

Inspect all of the components in the air circuit forthe starting motor. Inspect all of the air lines andconnections for leaks.

If the teeth of the starting motor pinion and/or theflywheel ring gear are damaged, the air circuit forthe starting motor must be examined in order todetermine the cause of the problem.

Removal and Installation of theStarting MotorRefer to the Service Manual, “Disassembly andAssembly” module for information on removing thestarting motor and installing the starting motor.


i01218172

Stator Lead - CheckSMCS Code: 4459-535

Visually inspect the following areas for cracking andphysical damage:

• stator output leads

• protective sleeving

• insulation

126 SEBU6682-08Maintenance SectionStator Winding Temperature - Measure/Record

i02514961

Stator Winding Temperature -Measure/RecordSMCS Code: 4453-082-TA

Some generators are provided with optional 100 OhmResistance Temperature Detectors (RTD). When thetemperature of the stator winding is suspected to behigh, measure the temperature. If the generator isfurnished with Resistance Temperature Detectors,the detectors are installed in the slots of the mainarmature (stator). The detectors are used withequipment that is available from the factory. Thisequipment is used in order to measure the mainarmature’s winding temperature.

i01012850

Turbocharger - InspectSMCS Code: 1052-040

Periodic inspection and cleaning is recommendedfor the turbocharger.

Fouling of the turbine wheels can contribute to loss ofengine power and overall loss of engine efficiency.

If the turbocharger fails during engine operation,damage to the turbocharger compressor wheeland/or to the engine may occur. Damage to theturbocharger compressor wheel could allow partsfrom the compressor wheel to enter an enginecylinder. This can cause additional damage to thepistons, the valves, and the cylinder head.

NOTICETurbocharger bearing failures can cause large quan-tities of oil to enter the air inlet and exhaust systems.Loss of engine lubricant can result in serious enginedamage.

Minor leakage of a turbocharger housing under ex-tended low idle operation should not cause problemsas long as a turbocharger bearing failure has not oc-curred.

When a turbocharger bearing failure is accompaniedby a significant engine performance loss (exhaustsmoke or engine rpm up at no load), do not continueengine operation until the turbocharger is repaired orreplaced.

An inspection of the turbocharger can minimizeunscheduled downtime. Also, the chance for potentialdamage to other engine parts is reduced.

Note: Turbocharger components require clearancesthat are precise. The turbocharger cartridge must bebalanced due to high rpm.

The following conditions can cause the turbochargerto be out-of-balance:

• The buildup of deposits

• Chipping and/or flaking of deposits

If the turbocharger must be removed for inspection,use caution. Do not break deposits from the turbinewheel. Do not attempt to clean the turbine wheel. Foroptions regarding removal, installation, repair andreplacement, see the Service Manual or consult yourCaterpillar dealer.

1. Remove the exhaust outlet piping and removethe air inlet piping from the turbocharger. Visuallyinspect the piping for the presence of oil.

2. Turn the compressor wheel and the turbine wheelby hand. The assembly should turn freely. Inspectthe compressor wheel and the turbine wheel forcontact with the turbocharger housing. Thereshould not be any visible signs of contact betweenthe turbine wheel or compressor wheel and theturbocharger housing. If there is any indication ofcontact between the rotating turbine wheel or thecompressor wheel and the turbocharger housing,the turbocharger should be reconditioned.

3. Check the compressor wheel for cleanliness.If only the blade side of the wheel is dirty, dirtand/or moisture is passing through the air filteringsystem. If oil is found only on the back side of thewheel, there is a possibility of a failed turbochargeroil seal.

The presence of oil may be the result of extendedengine operation at low idle. The presence of oilmay also be the result of a restriction of the linefor the inlet air (plugged air filters), which causesthe turbocharger to slobber.

Note: Deposits can accumulate on the turbine wheel.The turbine wheel will become unbalanced when thedeposits flake off. The turbocharger cartridge mustbe replaced when this occurs. However, removedeposits from the housing. This will prevent wear onthe blades of the turbine wheel.

4. Inspect the turbine wheel for deposits. If depositsof 25 mm (1/16 inch) thickness are found or ifthe turbine is in contact with the housing, theturbocharger must be disassembled and cleaned.The deposits can be very difficult to remove.

5. Inspect the bore of the turbine housing forcorrosion and deposits.


Valve Stem Projection - Measure/Record

6. Clean the turbocharger compressor housing withstandard shop solvents and a soft bristle brush.

7. Check the clearances of the turbocharger bearing.Compare the clearances to the Service Manual,“Specifications”. If the clearances are not withinthe specifications, the turbocharger must berepaired.

8. Fasten the air inlet piping and the exhaust outletpiping to the turbocharger housing.

i01360109

Valve Stem Projection -Measure/RecordSMCS Code: 1105-082

Valve Recession – The valves and the valve seatsare worn over time. This causes the valves to recedeinto the cylinder head. This condition is called “valverecession”.

The exhaust valves and valve seats show thegreatest wear due to high operating temperatures.The top end overhaul is normally scheduledaccording to the exhaust valve recession.

It is difficult to obtain an accurate measurement ofvalve recession inside the cylinder head. Use thefollowing method in order to determine the valverecession:

1. Remove the valve cover. For instructions, see theService Manual, “Disassembly and Assembly”module.

2. Move the rocker arm from the top of the valvestem.

3. Use a depth micrometer. Obtain the measurementfrom the tip of the valve stem to the cylinder head.Obtain this measurement for each exhaust valve.

Make several copies of this Operation andMaintenance Manual, “Valve Data Sheet” (ReferenceMaterials Section). Record the measurements onthe sheets.

• The projection of the exhaust valve stemsshould be measured after completion of the initialstart-up tests and the engine commissioning. Thismeasurement is the baseline. The baseline is areference for subsequent measurements.

• Measure the projection of the exhaust valverotators at the first oil change interval. Illustration97 shows schedules for determining subsequentintervals.

128 SEBU6682-08Maintenance SectionValve Stem Projection - Measure/Record


(A) Schedule(B) Schedule(C) Schedule

(Y) Valve recession in millimeters (inches)(X) Hours of operation(1) 0.254 mm (0.0100 inch)

(2) 0.218 mm (0.0086 inch)(3) 0.152 mm (0.0060 inch)

To determine intervals, use the point on the graph inIllustration 97 that is closest to the measurement foreach cylinder.

For example, suppose that the measurement thatwas obtained at the initial oil change shows a valverecession of approximately 0.152 mm (0.0060 inch).According to Schedule (C), the next interval formeasuring that cylinder is at 5000 service hours.Another cylinder may have a valve recession ofapproximately 0.254 mm (0.0100 inch). Accordingto Schedule (A), the next interval for measuring thatcylinder is at 3000 service hours.

• After 70 percent of the maximum limit has beenreached, measure the projection of the exhaustvalve stems at every 750 hours of operation(turbocharged engines). For Naturally aspiratedengines, perform the measurement at every 1500hours of operation.

• Plan for the top end overhaul as the valvestem projection approaches the maximum limit.Perform the top end overhaul when the valve stemprojection has increased by a total of 2.3 mm(0.09 inch). Do not allow the valve recessionto exceed this limit. The valve head can break.This will cause severe damage in the combustionchamber and the turbocharger.



Varistor - Test

i01494879

Varistor - TestSMCS Code: 4466-081


PMPE Generator Wiring Diagram(CR1-CR6) Diodes(CR7) Varistor(L1) Exciter field (stator)(L2) Exciter armature (rotor)(L3) Main field (rotor)(L4) Main armature (stator)(L5) Pilot exciter armature(PM) Permanent magnet(RFA) Rotating field assembly(CST) Customer supplied transformer

OhmmeterAn ohmmeter can be used to check a varistor(CR7). Place an ohmmeter across the varistor. Theresistance should be a minimum of 15000 ohms. Ifthe resistance is less than 15000 ohms, the varistoris faulty.

Test Light

g00555113Illustration 99Test Light

Refer to the test light that is shown in Illustration 99.Follow these steps in order to test the varistor:

1. Disconnect either lead of the varistor (CR7).

2. Place the test light across the varistor.

3. Observe the results. The lamp should not light.

4. Reverse the test light.

5. Observe the results. The lamp should not light.

If the test light illuminates in either direction, there isa short in the varistor. Replace any faulty varistorswith varistors that have comparable operatingcharacteristics. Include the following informationwhen a varistor is being ordered for replacement:

• Part number of the varistor

• Serial number of the generator

After the varistor has been replaced, verify that thestrapping of the field winding lead is securely woundon the shaft. Also, verify that the strapping of the fieldwinding lead is securely tied.

i01492446

Walk-Around InspectionSMCS Code: 1000-040

Inspect the Engine for Leaks andfor Loose ConnectionsA walk-around inspection should only take a fewminutes. When the time is taken to perform thesechecks, costly repairs and accidents can be avoided.

130 SEBU6682-08Maintenance SectionWalk-Around Inspection

For maximum engine service life, thoroughly inspectthe engine room before starting the engine. Look foritems such as leaks, loose bolts, loose connectionsand trash buildup. Make repairs, as needed.

• The guards must be in the proper place. Repairdamaged guards or replace missing guards.

• Wipe all caps and plugs before the engine isserviced in order to reduce the chance of systemcontamination.

NOTICEFor any type of leak, clean up the fluid. If leaking is ob-served, find the source and correct the leak. If leakingis suspected, check the fluid levels more often thanrecommended until the leak is found or fixed, or untilthe suspicion of a leak is proved to be unwarranted.

NOTICEAccumulated grease and/or oil on an engine or deck isa fire hazard. Remove this debris with steam cleaningor high pressure water.

• Ensure that cooling lines are properly clamped.Check for leaks. Check the condition of all pipes.

• Inspect the water pumps for coolant leaks.

Note: The water pump seal is lubricated by coolantin the cooling system. It is normal for a small amountof leakage to occur when the engine cools and theparts contract.

Excessive coolant leakage may indicate the needto replace the water pump seal. For instructionson removal and installation of water pumps and/orseals, refer to the Service Manual, “Disassembly andAssembly” module for the engine or consult yourCaterpillar dealer.

• Inspect the lubrication system for leaks at the frontcrankshaft seal, the rear crankshaft seal, the oilpan, the oil filters and the valve covers.

NEVER use a flame to check for gas leaks. Use agas detector.

An open flame can ignite mixtures of air and fuel.This will cause explosion and/or fire which couldresult in severe personal injury or death.

• Check the fuel system for leaks. Look for loose fuelline clamps.

• Inspect the piping for the air inlet system and theelbows for cracks and for loose clamps.

• Inspect the wiring and the wiring harnesses forloose connections and for worn wires or frayedwires.

• Inspect the ground straps for good connectionsand for good condition.

• Check the condition of the gauges. Replace anygauge that is damaged. Replace any gauge thatcan not be calibrated.

• Inspect the exhaust system for leaks. If a leak isfound, make repairs.

i01041757

Walk-Around Inspection(Exercise Inspection ofStandby Generator SetEngines)SMCS Code: 1000-040

NEVER use a flame to check for gas leaks. Use agas detector.

An open flame can ignite mixtures of air and fuel.This will cause explosion and/or fire which couldresult in severe personal injury or death.

1. Perform the procedures that are described inthis Operation and Maintenance Manual, “BeforeStarting Engine” topic (Operation Section).

2. Start the engine according to the instructions inthis Operation and Maintenance Manual, “EngineStarting” topic (Operation Section).

NOTICEFor any type of leak (coolant, lube, or fuel) clean up thefluid. If leaking is observed, find the source and correctthe leak. If leaking is suspected, check the fluid levelsmore often than recommended until the leak is foundor fixed, or until the suspicion of a leak is proved to beunwarranted.

3. Perform an inspection of the installation afterthe engine is started. Look for leaks. Listen forunusual noises.

• Check the engine oil level when the engine isoperating at low idle rpm. Observe the oil levelon the “LOW IDLE” side of the oil level gauge(dipstick).

SEBU6682-08 131Maintenance SectionWater Pump - Inspect

• Inspect the lubrication system for leaks at theoil pan, the oil filter, and the valve covers.

• Inspect the cooling system for leaks at the hoseconnections.

• Check the fuel system for leaks with a gasdetector.

• Inspect the piping for the air inlet system andthe elbows for cracks and for loose clamps.

• Inspect the exhaust system for leaks.

• If the enclosure has louvers, inspect the louversfor proper operation.

• Observe the gauges. Ensure the correctreadings for the engine rpm. Record the engineoil pressure and the jacket water temperature.

• Record the data for the performance of thegenerator. See the Operation and MaintenanceManual for the generator and the control panel.

4. After exercising the generator set, stop the engineaccording to this Operation and MaintenanceManual, “Engine Stopping” topic (OperationSection).

5. Perform the procedures that are described inthis Operation and Maintenance Manual, “AfterStopping Engine” topic (Operation Section).

6. Ensure that the control switches are in the correctposition for automatic starting of the generator set.

i00524084

Water Pump - InspectSMCS Code: 1361-040

A failed water pump might cause severe engineoverheating problems that could result in cracks inthe cylinder head, a piston seizure or other potentialdamage to the engine.

Visually inspect the water pump for leaks. If leakingof the water pump seals is observed, replace all ofthe water pump seals. Refer to the Service Manualfor the disassembly and assembly procedure.

Inspect the water pump for wear, cracks, pin holesand proper operation. Refer to the Service Manual orconsult your Caterpillar dealer if repair is needed orreplacement is needed.

i01023425

Water Temperature Regulator -ReplaceSMCS Code: 1355-510

Replace the water temperature regulators beforethe water temperature regulators fail. This is arecommended preventive maintenance practice.Replacing the water temperature regulators reducesthe chances for unscheduled downtime.

A water temperature regulator that fails in apartially opened position can cause overheating orovercooling of the engine.

A water temperature regulator that fails in the closedposition can cause excessive overheating. Excessiveoverheating could result in cracking of the cylinderhead or a seizure of the pistons.

A water temperature regulator that fails in the openposition will cause the engine operating temperatureto be too low during partial load operation. Lowengine operating temperatures during partial loadscould cause an excessive carbon buildup inside thecylinders. This excessive carbon buildup could resultin an accelerated wear of the piston rings and wearof the cylinder liner. Also, a low temperature canallow moisture to condense in the oil. This can formdamaging acids.

NOTICEFailure to replace the water temperature regulatorson a regularly scheduled basis could cause severeengine damage.

Never operate the engine without the water tempera-ture regulators installed.

If the water temperature regulator is installed incor-rectly, the enginemay overheat, causing cylinder headdamage. Ensure that the new water temperature reg-ulator is installed in the original position.

For the procedure to replace the water temperatureregulators, see the Service Manual, “Disassemblyand Assembly” module. Consult your Caterpillardealer for assistance.

Note: If only the water temperature regulators arereplaced, drain the coolant from the cooling system toa level that is below the water temperature regulatorhousing.

132 SEBU6682-08Maintenance SectionWinding - Test

i01787397

Winding - TestSMCS Code: 4453-081; 4454-081; 4457-081;4470-081


PMPE Generator Wiring Diagram

(CR1-CR6) Diodes(CR7) Varistor(L1) Exciter field (stator)(L2) Exciter armature (rotor)(L3) Main field (rotor)(L4) Main armature (stator)(L5) Pilot exciter armature(PM) Permanent magnet(RFA) Rotating field assembly(CST) Customer supplied transformer

Table 28

Tools Needed

Part Number Part(1) Quantity

6V-7070 DigitalMultimeter 1

146-4080Digital

Multimeter(RS232)

1

(1) Only one multimeter is necessary for this test. Either of themultimeters that are shown will work.



Measure the resistance of the following windings:(L1), (L2), (L3), (L4), and (L5). The winding thatis being tested must be disconnected from theother components before the resistance can bemeasured. The following resistance measurementsare approximations. If the measured value isnot near the listed approximation, the winding isprobably damaged. For a more precise resistancevalue, consult the Technical Marketing Information(TMI). Refer to the generator arrangement that is inquestion.

Note: The winding temperature affects theresistance. When the winding temperature increases,the winding resistance also increases. Whenthe winding temperature decreases, the windingresistance also decreases. Therefore, a correctmeasurement can be performed only when thewinding is at room temperature.

The following armature windings have very littleresistance: (L2), (L4), and (L5). The resistance ofthese windings will measure near 0 ohms. Use amilliohmmeter to measure the resistance of thearmature windings.

Exciter Armature (Rotor) (L2) – less than 0.1 ohm

Main armature (Stator) (L4) – less than 0.1 ohm

Pilot Exciter Armature (L5) – less than 0.1 ohm

Use a multimeter in order to measure the resistanceof field windings (L1) and (L3).

Exciter Field (Stator) (L1) – approximately 3.0ohms to 6.0 ohms

Main Field (Rotor) (L3) – approximately 0.75 ohmsto 2.0 ohms

Note: There should be no continuity between anywinding and ground. There should be no continuitybetween any winding and another winding.

g3408 and g3412 engines maintenance intervals

Documents