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HYDRAULIC

EXCAVATOR

SEN01968-02

PC138US -8PC138USLC-8

SERIAL NUMBERS PC138US- 20001PC138USLC- 20001 and up

PC138US, USLC-8 1

SEN01977-02

HYDRAULIC EXCAVATOR1SHOP MANUAL

PC138US-8PC138USLC-8

Machine model Serial number

PC138US-8 20001 and upPC138USLC-8 20001 and up

00 Index and foreword 1IndexComposition of shop manual .......................................................................................................................... 2Table of contents............................................................................................................................................. 4

SEN01977-02 00 Index and foreword

2 PC138US, USLC-8

Composition of shop manual 1The contents of this shop manual are shown together with Form No. in a list.Note 1: Always keep the latest version of this manual in accordance with this list and utilize accordingly.

The marks shown to the right of Form No. denote the following:QQQQ: New issue (to be filed additionally) q: Revision (to be replaced for each Form No.)

Note 2: This shop manual can be supplied for each Form No.

Note 3: To file this shop manual in the special binder for management, handle it as follows: Place a divider on the top of each section in the file after matching the Tub No. with No. indicated

next to each Section Name shown in the table below: File overview and other materials in sections in the order shown below and utilize them accord-

ingly.

Section Title Form Number

Shop Manual, contents binder, binder label and tabs SEN01968-02

00 Index and foreword SEN01969-02Index SEN01977-02 qForeword and general information SEN01978-01 q

01 Specification SEN01970-01Specification and technical data SEN01979-01

10 Structure, function and maintenance standard SEN01971-02Engine and cooling system SEN02545-01Power train SEN02546-01Undercarriage and frame SEN02547-01Hydraulic system, Part 1 SEN02548-01Hydraulic system, Part 2 SEN02549-02 qHydraulic system, Part 3 SEN02550-01Work equipment SEN02551-00Cab and its attachments SEN02552-01Electrical system SEN02553-01

20 Standard value table SEN01972-01Standard service value table SEN02457-01

30 Testing and adjusting SEN01973-01Testing and adjusting, Part 1 SEN02458-01Testing and adjusting, Part 2 SEN02459-00Testing and adjusting, Part 3 SEN02460-01

40 Troubleshooting SEN01974-01Failure code table and fuse locations SEN02461-01General information on troubleshooting SEN02462-00Troubleshooting by failure code, Part 1 SEN02463-01Troubleshooting by failure code, Part 2 SEN02464-01Troubleshooting by failure code, Part 3 SEN02465-01Troubleshooting by failure code, Part 4 SEN02466-00Troubleshooting of electrical system (E-mode) SEN02467-00

00 Index and foreword SEN01977-02

PC138US, USLC-8 3

Troubleshooting of hydraulic and mechanical system (H-mode) SEN02468-01Troubleshooting of engine (S-mode) SEN02469-01

50 Disassembly and assembly SEN01975-00General information on disassembly and assembly SEN02709-00Engine and cooling system SEN02710-00Power train SEN02711-00Undercarriage and frame SEN02712-00Hydraulic system SEN02713-00Work equipment Body SEN02714-00Cab and its attachments SEN02715-00Electrical system SEN02716-00

90 Diagrams and drawings SEN01976-01Hydraulic circuit diagram SEN01980-00Electrical diagrams and drawings SEN01981-01


4 PC138US, USLC-8

Table of contents 100 Index and foreword

Index SEN01977-02Composition of shop manual....................................................................................................... 2Table of contents ......................................................................................................................... 4

Foreword and general information SEN01978-01Safety notice................................................................................................................................ 2How to read the shop manual ..................................................................................................... 7Explanation of terms for maintenance standard.......................................................................... 9Handling of electric equipment and hydraulic component........................................................... 11Handling of connectors newly used for engines.......................................................................... 20How to read electric wire code .................................................................................................... 23Precautions when carrying out operation .................................................................................... 26Method of disassembling and connecting push-pull type coupler ............................................... 29Standard tightening torque table ................................................................................................. 32Conversion table ......................................................................................................................... 36

01 SpecificationSpecification and technical data SEN01979-01

Specification dimension drawings ............................................................................................... 2Working range diagram ............................................................................................................... 3Specifications .............................................................................................................................. 4List of weights.............................................................................................................................. 10Table of fuel, coolant and lubricants ............................................................................................ 14

10 Structure, function and maintenance standardEngine and cooling system SEN02545-01

Engine mount .............................................................................................................................. 2PTO ............................................................................................................................................. 3Cooling system............................................................................................................................ 4

Power train SEN02546-01Power train .................................................................................................................................. 2Swing circle ................................................................................................................................. 3Swing machinery ......................................................................................................................... 4

Undercarriage and frame SEN02547-01Track frame ................................................................................................................................. 2Idler cushion ................................................................................................................................ 4Idler ............................................................................................................................................. 6Track roller................................................................................................................................... 7Carrier roller ................................................................................................................................ 8Sprocket ...................................................................................................................................... 9Track shoe................................................................................................................................... 10

Hydraulic system, Part 1 SEN02548-01Hydraulic equipment layout drawing ........................................................................................... 2Valve control................................................................................................................................ 4Hydraulic tank and filter............................................................................................................... 6Hydraulic pump ........................................................................................................................... 8

Hydraulic system, Part 2 SEN02549-02Control valve ............................................................................................................................... 2CLSS........................................................................................................................................... 14Functions and operation by valve................................................................................................ 18

Hydraulic system, Part 3 SEN02550-01PPC valve.................................................................................................................................... 2


PC138US, USLC-8 5

Swing motor ................................................................................................................................ 19Travel motor ................................................................................................................................ 27Center swivel joint ....................................................................................................................... 36Solenoid valve............................................................................................................................. 40PPC accumulator ........................................................................................................................ 44Holding valve............................................................................................................................... 46Multi-control valve ....................................................................................................................... 51

Work equipment SEN02551-00Work equipment .......................................................................................................................... 2Dimensions of components......................................................................................................... 4Hydraulic cylinder........................................................................................................................ 8

Cab and its attachments SEN02552-01Air conditioner ............................................................................................................................. 2

Electrical system SEN02553-01Electronic control system ............................................................................................................ 2Monitor system............................................................................................................................ 35KOMTRAX system ...................................................................................................................... 49Sensor......................................................................................................................................... 51

20 Standard value tableStandard service value table SEN02457-01

Standard value table for engine related parts.............................................................................. 2Standard value table for chassis related parts ............................................................................ 3

30 Testing and adjustingTesting and adjusting, Part 1 SEN02458-01

Tools for testing, adjusting, and troubleshooting ......................................................................... 3Testing engine speed .................................................................................................................. 6Testing exhaust temperature....................................................................................................... 7Checking exhaust gas color ........................................................................................................ 8Adjusting valve clearance ........................................................................................................... 9Testing compression pressure .................................................................................................... 11Testing blow-by pressure ............................................................................................................ 13Testing engine oil pressure ......................................................................................................... 14Handling fuel system parts .......................................................................................................... 15Releasing residual pressure from fuel system ............................................................................ 15Testing fuel pressure ................................................................................................................... 16Testing fuel return rate and fuel leakage ..................................................................................... 17Bleeding air from fuel circuit........................................................................................................ 19Checking fuel circuit for leakage ................................................................................................. 21Testing and adjusting alternator belt tension............................................................................... 22Testing swing circle bearing clearance........................................................................................ 23Checking and adjusting air conditioner compressor belt tension ................................................ 24Checking and adjusting track shoe tension................................................................................. 25Testing and adjusting oil pressure in work equipment, swing, and travel circuits........................ 27Testing control circuit basic pressure .......................................................................................... 30Testing and adjusting oil pressure in pump PC control circuit ..................................................... 31Testing and adjusting oil pressure in pump LS control circuit ..................................................... 34Testing solenoid valve output pressure ....................................................................................... 38Testing PPC valve output pressure ............................................................................................. 39Adjusting play of work equipment and swing PPC valves........................................................... 41Checking parts which cause hydraulic drift of work equipment................................................... 42Testing and adjusting travel deviation ......................................................................................... 44Releasing residual pressure from hydraulic circuit...................................................................... 46Testing oil leakage....................................................................................................................... 47Bleeding air from each part ......................................................................................................... 50


6 PC138US, USLC-8

Checking cab tipping stopper ...................................................................................................... 52Adjusting mirrors ......................................................................................................................... 52

Testing and adjusting, Part 2 SEN02459-00Special functions of machine monitor.......................................................................................... 2

Testing and adjusting, Part 3 SEN02460-01Handling voltage circuit of engine controller................................................................................ 2Preparation work for troubleshooting of electrical system........................................................... 3Procedure for testing diodes ....................................................................................................... 8Pm Clinic service......................................................................................................................... 9

40 TroubleshootingFailure code table and fuse locations SEN02461-01

Failure code table........................................................................................................................ 2Fuse locations ............................................................................................................................. 6

General information on troubleshooting SEN02462-00Points to remember when troubleshooting.................................................................................. 2Sequence of events in troubleshooting ....................................................................................... 3Checks before troubleshooting.................................................................................................... 4Classification and procedures for troubleshooting ...................................................................... 5Information in troubleshooting table ............................................................................................ 6Phenomena looking like troubles and troubleshooting Nos. ....................................................... 8Wiring table for connector pin numbers....................................................................................... 11T-adapter box and T-adapter table .............................................................................................. 44

Troubleshooting by failure code, Part 1 SEN02463-01Failure code [989L00] Engine controller lock caution 1............................................................... 3Failure code [989M00] Engine controller lock caution 2.............................................................. 3Failure code [989N00] Engine controller lock caution 3 .............................................................. 4Failure code [AB00KE] Charge voltage low ................................................................................ 6Failure code [B@BAZG] Eng oil press. low................................................................................. 8Failure code [B@BAZK] Eng oil level low ................................................................................... 8Failure code [B@BCNS] Eng coolant overheat........................................................................... 9Failure code [B@HANS] Hydr oil overheat ................................................................................. 9Failure code [CA111] ECM critical internal failure ....................................................................... 10Failure code [CA115] Eng. Ne and Bkup speed sensor error ..................................................... 13Failure code [CA122] Charge air press sensor high error........................................................... 14Failure code [CA123] Charge air press sensor low error ............................................................ 16Failure code [CA131] Throttle sensor high error ......................................................................... 18Failure code [CA132] Throttle sensor low error........................................................................... 20Failure code [CA144] Coolant temp. sensor high error ............................................................... 21Failure code [CA145] Coolant temp. sensor low error ................................................................ 22Failure code [CA153] Charge air temp. sensor high error........................................................... 23Failure code [CA154] Charge air temp. sensor low error ............................................................ 24Failure code [CA187] Sensor sup. 2 volt. low error..................................................................... 24Failure code [CA221] Ambient air press. sensor high error ........................................................ 26Failure code [CA222] Ambient air press. sensor low error.......................................................... 28Failure code [CA227] Sensor sup. 2 volt. high error ................................................................... 30Failure code [CA234] Eng. overspeed ........................................................................................ 32Failure code [CA238] Ne speed sensor sup. volt. error .............................................................. 34Failure code [CA271] IMV/PCV1 short error ............................................................................... 36Failure code [CA272] IMV/PCV1 open error ............................................................................... 37Failure code [CA322] Injector #1 (L #1) system open/short error ............................................... 38Failure code [CA324] Injector #3 (L/B #3) system open/short error ............................................ 40Failure code [CA331] Injector #2 (L/B #2) system open/short error ............................................ 42Failure code [CA332] Injector #4 (L/B #4) system open/short error ............................................ 44

Troubleshooting by failure code, Part 2 SEN02464-01Failure code [CA351] Inj. drive circuit error ................................................................................. 3


PC138US, USLC-8 7

Failure code [CA352] Sensor sup. 1 volt. low error..................................................................... 6Failure code [CA386] Sensor sup. 1 volt. high error ................................................................... 8Failure code [CA435] Abnormality in engine oil pressure switch ................................................ 10Failure code [CA441] Battery voltage low error .......................................................................... 11Failure code [CA442] Battery voltage high error ......................................................................... 11Failure code [CA449] Rail press. very high error ........................................................................ 12Failure code [CA451] Rail press. sensor high error .................................................................... 14Failure code [CA452] Rail press. sensor low error...................................................................... 16Failure code [CA553] Rail press. high error ................................................................................ 16Failure code [CA559] Rail press. low error ................................................................................. 17Failure code [CA689] Eng. Ne speed sensor error ..................................................................... 20Failure code [CA731] Eng. Bkup speed sensor phase error....................................................... 22Failure code [CA757] All persistent data lost error...................................................................... 22Failure code [CA778] Eng. Bkup speed sensor error.................................................................. 24Failure code [CA1633] KOMNET datalink timeout error ............................................................. 26Failure code [CA2185] Throttle sens. sup. volt. high error.......................................................... 28Failure code [CA2186] Throttle sens. sup. volt. low error ........................................................... 30Failure code [CA2249] Rail press. very low error........................................................................ 30Failure code [CA2311] Abnormality in IMV solenoid ................................................................... 31Failure code [D110KB] Battery relay drive short ......................................................................... 32Failure code [D19JKZ] Personal code relay abnormality ............................................................ 34Failure code [D862KA] GPS antenna discon .............................................................................. 36Failure code [DA22KK] Pump solenoid power low error ............................................................. 38Failure code [DA25KP] 5V sensor 1 power abnormality ............................................................. 40Failure code [DA26KP] 5V sensor 2 power abnormality ............................................................. 43

Troubleshooting by failure code, Part 3 SEN02465-01Failure code [DA2RMC] CAN discon (Pump controller detected)............................................... 4Failure code [DAF8KB] Short circuit in camera power supply .................................................... 6Failure code [DAFGMC] GPS module error................................................................................ 8Failure code [DAFRMC] CAN discon (Monitor detected)............................................................ 10Failure code [DGH2KB] Hydr oil sensor short............................................................................. 12Failure code [DHPAMA] Pump press sensor abnormality........................................................... 14Failure code [DHSFMA] Travel left forward PPC press sensor abnormality ............................... 16Failure code [DHSGMA] Travel right forward PPC press sensor abnormality ............................ 18Failure code [DHSHMA] Travel left reverse PPC press sensor abnormality............................... 20Failure code [DHSJMA] Travel right reverse PPC press sensor abnormality ............................. 22Failure code [DHSKMA] Blade raise PPC press sensor abnormality ......................................... 24Failure code [DHSLMA] Blade lower PPC press sensor abnormality ......................................... 26Failure code [DHX1MA] Overload sensor abnormality (Analog)................................................. 28Failure code [DV20KB] Travel alarm S/C.................................................................................... 29Failure code [DW43KA] Travel speed sol discon ........................................................................ 30Failure code [DW43KB] Travel speed sol short .......................................................................... 31Failure code [DW45KA] Swing brake sol discon......................................................................... 32Failure code [DW45KB] Swing brake sol short ........................................................................... 34Failure code [DW91KA] Travel junction sol discon ..................................................................... 36Failure code [DW91KB] Travel junction sol short........................................................................ 37Failure code [DWJ0KA] Merge-divider sol discon....................................................................... 38Failure code [DWJ0KB] Merge-divider sol short ......................................................................... 39

Troubleshooting by failure code, Part 4 SEN02466-00Failure code [DXA8KA] PC-EPC sol discon................................................................................ 2Failure code [DXA8KB] PC-EPC sol short .................................................................................. 4Failure code [DXE4KA] Service current EPC discon .................................................................. 6Failure code [DXE4KB] Service current EPC short..................................................................... 7Failure code [DY20KA] Wiper working abnormality .................................................................... 8Failure code [DY20MA] Wiper parking abnormality .................................................................... 10Failure code [DY2CKA] Washer drive discon.............................................................................. 12Failure code [DY2CKB] Washer drive short ................................................................................ 14


8 PC138US, USLC-8

Failure code [DY2DKB] Wiper drive (for) short ........................................................................... 16Failure code [DY2EKB] Wiper drive (rev) short........................................................................... 18

Troubleshooting of electrical system (E-mode) SEN02467-00Before carrying out troubleshooting of electrical system............................................................. 3Information in troubleshooting table ............................................................................................ 5E-1 When starting switch turned ON, machine monitor displays nothing.................................... 6E-2 When starting switch turned ON (before starting engine), basic check item lights up .......... 8E-3 Engine does not start (Engine does not turn) ....................................................................... 9E-4 Preheater does not operate .................................................................................................. 12E-5 Automatic warm-up system does not operate (in cold season) ............................................ 14E-6 All work equipment, swing, and travel mechanism do not move or cannot be locked.......... 16E-7 Precaution lights up while engine is running......................................................................... 18E-8 Emergency stop item lights up while engine is running ........................................................ 21E-9 Engine coolant temperature gauge does not indicate normally............................................ 22E-10 Hydraulic oil temperature gauge does not indicate normally .............................................. 23E-11 Fuel level gauge does not indicate normally....................................................................... 25E-12 Contents of display by machine monitor are different from applicable machine................. 27E-13 Machine monitor does not display some items................................................................... 27E-14 Function switch does not work............................................................................................ 27E-15 Auto-decelerator does not operate normally....................................................................... 28E-16 Working mode does not change ......................................................................................... 29E-17 Travel speed does not change............................................................................................ 30E-18 Alarm buzzer cannot be stopped ........................................................................................ 31E-19 Windshield wiper and window washer do not operate........................................................ 32E-20 Swing holding brake does not operate normally................................................................. 36E-21 Travel alarm does not sound or does not stop sounding.................................................... 38E-22 Air conditioner does not operate normally (including air conditioner abnormality record) .. 39E-23 While starting switch is in OFF position, service meter is not displayed............................. 51E-24 Machine monitor cannot be set in service mode ................................................................ 51E-25 Monitoring function does not display lever control signal normally..................................... 52E-26 KOMTRAX system does not operate normally ................................................................... 68

Troubleshooting of hydraulic and mechanical system (H-mode) SEN02468-01Information contained in troubleshooting table............................................................................ 3System chart for hydraulic and mechanical systems .................................................................. 4H-1 Speed or power of all work equipment, swing, and travel are low........................................ 6H-2 Engine speed sharply drops or engine stalls ........................................................................ 7H-3 No work equipment, travel and swing move......................................................................... 8H-4 Abnormal noise is heard from around hydraulic pump ......................................................... 8H-5 Fine control mode does not function .................................................................................... 9H-6 Speed or power of boom is low ............................................................................................ 10H-7 Speed or power of arm is low ............................................................................................... 11H-8 Speed or power of bucket is low........................................................................................... 12H-9 Work equipment does not move in its single operation ........................................................ 13H-10 Hydraulic drift of work equipment is large........................................................................... 14H-11 Time lag of work equipment is large ................................................................................... 15H-12 Work equipment loaded more is slower during compound operation................................. 15H-13 Boom RAISE speed is low in compound operation of swing + boom RAISE..................... 15H-14 Travel speed lowers largely during compound operation of work equipment/swing + travel .. 16H-15 Machine deviates during travel........................................................................................... 17H-16 Travel speed is low............................................................................................................. 18H-17 Machine cannot be steered easily or steering power is low ............................................... 19H-18 Travel speed does not change or it is kept low or high....................................................... 20H-19 Track does not move (Only either side).............................................................................. 20H-20 Machine does not swing ..................................................................................................... 21H-21 Swing acceleration or swing speed is low .......................................................................... 22H-22 Excessive overrun when stopping swing............................................................................ 23H-23 When upper structure stops swinging, it makes large shock.............................................. 24


PC138US, USLC-8 9

H-24 When upper structure stops swinging, it makes large sound ............................................. 24H-25 Hydraulic drift of swing is large........................................................................................... 25H-26 Flow rate in attachment circuit cannot be adjusted ............................................................ 26

Troubleshooting of engine (S-mode) SEN02469-01Method of using troubleshooting chart ........................................................................................ 4S-1 Starting performance is poor ................................................................................................ 8S-2 Engine does not start............................................................................................................ 9S-3 Engine does not pick up smoothly........................................................................................ 12S-4 Engine stops during operations ............................................................................................ 13S-5 Engine does not rotate smoothly .......................................................................................... 14S-6 Engine lacks output (or lacks power).................................................................................... 15S-7 Exhaust smoke is black (incomplete combustion)................................................................ 16S-8 Oil consumption is excessive (or exhaust smoke is blue) .................................................... 17S-9 Oil becomes contaminated quickly ....................................................................................... 18S-10 Fuel consumption is excessive........................................................................................... 19S-11 Oil is in coolant (or coolant spurts back or coolant level goes down) ................................. 20S-12 Oil pressure drops .............................................................................................................. 21S-13 Oil level rises (Entry of coolant or fuel)............................................................................... 22S-14 Coolant temperature becomes too high (overheating) ....................................................... 23S-15 Abnormal noise is made ..................................................................................................... 24S-16 Vibration is excessive ......................................................................................................... 25

50 Disassembly and assemblyGeneral information on disassembly and assembly SEN02709-00

How to read this manual ............................................................................................................. 2List of adhesives ......................................................................................................................... 4Special tool list ............................................................................................................................ 7Sketche of special tool ................................................................................................................ 11

Engine and cooling system SEN02710-00Removal and installation of fuel supply pump assembly............................................................. 2Removal and installation of fuel injector assembly ..................................................................... 4Removal and installation of front oil seal..................................................................................... 7Removal and installation of rear oil seal ..................................................................................... 9Removal and installation of cylinder head assembly .................................................................. 12Removal and installation of radiator assembly............................................................................ 19Removal and installation of aftercooler assembly ....................................................................... 21Removal and installation of work equipment oil cooler assembly ............................................... 23Removal and installation of engine and work equipment pump assembly.................................. 26Removal and installation of fuel tank assembly .......................................................................... 31

Power train SEN02711-00Removal and installation of travel motor and final drive assembly ............................................. 2Removal and installation of swing motor and swing machinery assembly.................................. 4Disassembly and assembly of swing machinery assembly......................................................... 6Removal and installation of swing circle assembly ..................................................................... 12

Undercarriage and frame SEN02712-00Disassembly and assembly of track roller................................................................................... 2Disassembly and assembly of idler assembly............................................................................. 5Disassembly and assembly of recoil spring ................................................................................ 8Removal and installation of of track shoe assembly ................................................................... 11Removal and installation of sprocket .......................................................................................... 13Removal and installation of revolving frame assembly ............................................................... 14Removal and installation of counterweight assembly (Machine without add-on weight)............. 16Removal and installation of counterweight assembly (Machine with add-on weight).................. 18

Hydraulic system SEN02713-00Removal and installation of center swivel joint assembly ........................................................... 2Disassembly and assembly of center swivel joint assembly ....................................................... 4


10 PC138US, USLC-8

Removal and installation of hydraulic tank assembly .................................................................. 5Removal and installation of hydraulic pump assembly................................................................ 8Removal and installation of control valve assembly.................................................................... 12Disassembly and assembly of control valve assembly ............................................................... 17Disassembly and assembly of work equipment PPC valve assembly ........................................ 27Disassembly and assembly of travel PPC valve assembly ......................................................... 30Disassembly and assembly of hydraulic cylinder assembly........................................................ 32

Work equipment Body SEN02714-00Removal and installation of work equipment assembly............................................................... 2

Cab and its attachments SEN02715-00Removal and installation of operator cab assembly.................................................................... 2Removal and installation of operator's cab glass (stuck glass) ................................................... 4Removal and installation of front window assembly.................................................................... 13Removal and installation of floor frame assembly....................................................................... 14

Electrical system SEN02716-00Removal and installation of air compressor assembly ................................................................ 2Removal and installation of air conditioner condenser................................................................ 3Removal and installation of air compressor unit assembly ......................................................... 4Removal and installation of machine monitor assembly ............................................................. 7Removal and installation of pump controller assembly ............................................................... 8Removal and installation of engine controller assembly ............................................................. 9Removal and installation of KOMTRAX communications module............................................... 10

90 Diagrams and drawingsHydraulic circuit diagram SEN01980-00

Hydraulic circuit diagram............................................................................................................. 3Electrical diagrams and drawings SEN01981-01

Electrical circuit diagram ............................................................................................................. 3Connectors table and arrangement drawing ............................................................................... 5


PC138US, USLC-8 11

12 PC138US, USLC-8


PC138US, USLC-8 Hydraulic excavator

Form No. SEN01977-02

2007 KOMATSUAll Rights ReservedPrinted in Japan 10-07 (02)

PC138US, USLC-8 1

SEN01978-01

HYDRAULIC EXCAVATOR1SHOP MANUAL

PC138US-8PC138USLC-8

Machine model Serial number

PC138US-8 20001 and upPC138USLC-8 20001 and up

00 Index and foreword 1Foreword and general informationSafety notice ................................................................................................................................................... 2How to read the shop manual ......................................................................................................................... 7Explanation of terms for maintenance standard ............................................................................................. 9Handling of electric equipment and hydraulic component .............................................................................11Handling of connectors newly used for engines ........................................................................................... 20How to read electric wire code...................................................................................................................... 23Precautions when carrying out operation...................................................................................................... 26Method of disassembling and connecting push-pull type coupler................................................................. 29Standard tightening torque table ................................................................................................................... 32Conversion table ........................................................................................................................................... 36


2 PC138US, USLC-8

(Rev. 2007/03)Safety notice 1Important safety noticeProper service and repair are extremely important for safe machine operation. The service and repairtechniques recommended by Komatsu and described in this manual are both effective and safe.Some of these techniques require the use of tools specially designed by Komatsu for the specificpurpose.To prevent injury to workers, the symbol kkkk is used to mark safety precautions in this manual. Thecautions accompanying these symbols should always be followed carefully. If any dangerous situa-tion arises or may possibly arise, first consider safety, and take the necessary actions to deal withthe situation.

1. General precautionsk Mistakes in operation are extremely

dangerous. Read the Operation andMaintenance Manual carefully beforeoperating the machine.

1) Before carrying out any greasing orrepairs, read all the safety plates stuck tothe machine. For the locations of thesafety plates and detailed explanation ofprecautions, see the Operation and Main-tenance Manual.

2) Decide a place in the repair workshop tokeep tools and removed parts. Alwayskeep the tools and parts in their correctplaces. Always keep the work area cleanand make sure that there is no dirt, water,or oil on the floor. Smoke only in the areasprovided for smoking. Never smoke whileworking.

3) When carrying out any operation, alwayswear safety shoes and helmet. Do notwear loose work clothes, or clothes withbuttons missing.q Always wear safety glasses when hit-

ting parts with a hammer.q Always wear safety glasses when

grinding parts with a grinder, etc.4) When carrying out any operation with 2 or

more workers, always agree on the oper-ating procedure before starting. Alwaysinform your fellow workers before startingany step of the operation. Before startingwork, hang UNDER REPAIR warningsigns in the operator's compartment.

5) Only qualified workers must carry out workand operation which require license orqualification.

6) Keep all tools in good condition, learn thecorrect way to use them, and use theproper ones of them. Before starting work,thoroughly check the tools, machine, fork-lift, service car, etc.

7) If welding repairs are needed, alwayshave a trained and experienced weldercarry out the work. When carrying outweld ing work, always wear weldinggloves, apron, shielding goggles, cap andother clothes suited for welding work.

8) Before starting work, warm up your bodythoroughly to start work under good condi-tion.

2. Preparations for work1) Before adding oil or making any repairs,

park the machine on hard and levelground, and apply the parking brake andblock the wheels or tracks to prevent themachine from moving.

2) Before starting work, lower the workequipment (blade, ripper, bucket, etc.) tothe ground. If this is not possible, insertthe lock pin or use blocks to prevent thework equipment from falling. In addition,be sure to lock all the control levers andhang warning signs on them.

Safety points1 Good arrangement2 Correct work clothes3 Following work standard4 Making and checking signs

5 Prohibition of operation and handling by unlicensed workers6 Safety check before starting work

7 Wearing protective goggles(for cleaning or grinding work)

8 Wearing shielding goggles and protectors (for welding work)9 Good physical condition and preparation

10 Precautions against work which you are not used to or you are used to too much


PC138US, USLC-8 3

3) When disassembling or assembling, sup-port the machine with blocks, jacks, orstands before starting work.

4) Remove all mud and oil from the steps orother places used to get on and off themachine. Always use the handrails, lad-ders or steps when getting on or off themach ine. Never jump on or o ff themachine. If it is impossible to use thehandrails, ladders or steps, use a stand toprovide safe footing.

3. Precautions during work1) Before disconnecting or removing compo-

nents of the oil, water, or air circuits, firstrelease the pressure completely from thecircuit. When removing the oil filler cap, adrain plug, or an oil pressure pickup plug,loosen it slowly to prevent the oil fromspurting out.

2) The coolant and oil in the circuits are hotwhen the engine is stopped, so be carefulnot to get scalded. Wait for the oil andcoolant to cool before carrying out anywork on the oil or water circuits.

3) Before starting work, stop the engine.When working on or around a rotatingpart, in particular, stop the engine. Whenchecking the machine without stoppingthe engine (measuring oi l pressure,revolving speed, temperature, etc.), takeextreme care not to get rolled or caught inrotating parts or moving parts.

4) Before starting work, remove the leadsfrom the battery. Always remove the leadfrom the negative () terminal first.

5) When raising a heavy component (heavierthan 25 kg), use a hoist or crane. Beforestarting work, check that the slings (wireropes, chains, and hooks) are free fromdamage. Always use slings which haveample capacity and install them to properplaces. Operate the hoist or crane slowlyto prevent the component from hitting anyother part. Do not work with any part stillraised by the hoist or crane.

6) When removing a cover which is underinternal pressure or under pressure from aspring, always leave 2 bolts in diagonalpositions. Loosen those bolts graduallyand alternately to release the pressure,and then remove the cover.

7) When removing components, be carefulnot to break or damage the electrical wir-ing. Damaged wiring may cause electricalfires.

8) When removing piping, stop the fuel or oilfrom spilling out. If any fuel or oil dripsonto the floor, wipe it up immediately. Fuelor oil on the floor can cause you to slipand can even start fires.

9) As a general rule, do not use gasoline towash parts. Do not use it to clean electri-cal parts, in particular.

10) Be sure to assemble all parts again in theiroriginal places. Replace any damagedparts and parts which must not be reusedwith new parts. When installing hoses andwires, be sure that they will not be dam-aged by contact with other parts when themachine is operated.

11) When installing high pressure hoses,make sure that they are not twisted. Dam-aged tubes a re dangerous , so beextremely careful when installing tubes forhigh pressure circuits. In addition, checkthat connect ing parts are cor rect lyinstalled.

12) When assembling or installing parts,always tighten them to the specifiedtorques. When installing protective partssuch as guards, or parts which vibrate vio-lently or rotate at high speed, be particu-lar ly carefu l to check that they areinstalled correctly.

13) When aligning 2 holes, never insert yourfingers or hand. Be careful not to get yourfingers caught in a hole.

14) When measuring hydraulic pressure,check that the measuring tools are cor-rectly assembled.

15) Take care when removing or installing thetracks of track-type machines. Whenremoving the track, the track separatessuddenly, so never let anyone stand ateither end of the track.

16) If the engine is operated for a long time ina place which is not ventilated well, youmay suffer from gas poisoning. Accord-ingly, open the windows and doors to ven-tilate well.


4 PC138US, USLC-8

4. Precautions for sling work and makingsigns1) Only one appointed worker must make

signs and co-workers must communicatewith each other frequently. The appointedsign maker must make specified signsclearly at a place where he is seen wellfrom the operator's seat and where he cansee the working condition easily. The signmaker must always stand in front of theload and guide the operator safely.q Do not stand under the load.q Do not step on the load.

2) Check the slings before starting slingwork.

3) Keep putting on gloves during sling work.(Put on leather gloves, if available.)

4) Measure the weight of the load by the eyeand check its center of gravity.

5) Use proper sling according to the weightof the load and method of slinging. If toothick wire ropes are used to sling a lightload, the load may slip and fall.

6) Do not sling a load with 1 wire rope alone.If it is slung so, it may rotate and may slipout of the rope. Install 2 or more wireropes symmetrically.k Slinging with 1 rope may cause

turning of the load during hoisting,untwisting of the rope, or slippingof the rope from its original wind-ing position on the load, which canresult in a dangerous accident.

7) Limit the hanging angle to 60, as a rule.Do not sling a heavy load with ropes form-ing a wide hanging angle from the hook.When hoisting a load with 2 or moreropes, the force subjected to each ropewill increase with the hanging angle. Thetable below shows the variation of allow-able load in kN {kg} when hoisting is madewith 2 ropes, each of which is allowed tosling up to 9.8 kN {1,000 kg} vertically, atvarious hanging angles. When the 2 ropessling a load vertically, up to 19.6 kN {2,000kg} of total weight can be suspended.This weight is reduced to 9.8 kN {1,000kg} when the 2 ropes make a hangingangle of 120. If the 2 ropes sling a 19.6kN {2,000 kg} load at a lifting angle of150, each of them is subjected to a forceas large as 39.2 kN {4,000 kg}.

8) When installing wire ropes to an angularload, apply pads to protect the wire ropes.If the load is slippery, apply proper mate-rial to prevent the wire rope from slipping.

9) Use the specified eyebolts and fix wireropes, chains, etc. to them with shackles,etc.

10) Apply wire ropes to the middle portion ofthe hook.q Slinging near the tip of the hook may

cause the rope to slip off the hookduring hoisting. The hook has themaximum strength at the middle por-tion.

11) Do not use twisted or kinked wire ropes.12) When lifting up a load, observe the follow-

ing.q Wind in the crane slowly until wire

ropes are stretched. When settlingthe wire ropes with the hand, do notgrasp them but press them fromabove. If you grasp them, your fingersmay be caught.

q After the wire ropes are stretched,stop the crane and check the condi-tion of the slung load, wire ropes, andpads.


PC138US, USLC-8 5

q If the load is unstable or the wire ropeor chains are twisted, lower the loadand lift it up again.

q Do not lift up the load slantingly.13) When lifting down a load, observe the fol-

lowing.q When lifting down a load, stop it tem-

porarily at 30 cm above the floor, andthen lower it slowly.

q Check that the load is stable, andthen remove the sling.

q Remove kinks and dirt from the wireropes and chains used for the slingwork, and put them in the specifiedplace.

5. Precautions for using mobile cranea Read the Operation and Maintenance

Manual of the crane carefully in advanceand operate the crane safely.

6. Precautions for using overhead hoist cranek When raising a heavy part (heavier

than 25 kg), use a hoist, etc. In Disas-sembly and assembly, the weight of apart heavier than 25 kg is indicatedafter the mark of 4444.

1) Before starting work, inspect the wireropes, brake, clutch, controller, rails, overwind stop device, electric shock preven-tion earth leakage breaker, crane collisionprevention device, and power applicationwarning lamp, and check safety.

2) Observe the signs for sling work.3) Operate the hoist at a safe place.4) Check the direction indicator plates (east,

west, south, and north) and the directionsof the control buttons without fail.

5) Do not sling a load slantingly. Do not movethe crane while the slung load is swinging.

6) Do not raise or lower a load while thecrane is moving longitudinally or laterally.

7) Do not drag a sling.8) When lifting up a load, stop it just after it

leaves the ground and check safety, andthen lift it up.

9) Consider the travel route in advance andlift up a load to a safe height.

10) Place the control switch on a positionwhere it will not be an obstacle to workand passage.

11) After operating the hoist, do not swing thecontrol switch.

12) Remember the position of the main switchso that you can turn off the power immedi-ately in an emergency.

13) If the hoist stops because of a power fail-ure, turn the power switch OFF. Whenturning on a switch which was turned OFFby the electric shock prevention earthleakage breaker, check that the devicesrelated to that switch are not in operationstate.

14) If you find an obstacle around the hoist,stop the operation.

15) After finishing the work, stop the hoist atthe specified position and raise the hookto at least 2 m above the floor. Do notleave the sling installed to the hook.

7. Selecting wire ropes1) Select adequate ropes depending on the

weight of parts to be hoisted, referring tothe table below.

a The allowable load is one-sixth of thebreaking strength of the rope used(Safety coefficient: 6).

Wire ropes(Standard Z twist ropes without galvanizing)

(JIS G3525, No. 6, Type 6X37-A)Nominal

diameter of rope Allowable load

mm kN ton10 8.8 0.912 12.7 1.314 17.3 1.716 22.6 2.318 28.6 2.920 35.3 3.625 55.3 5.630 79.6 8.140 141.6 14.450 221.6 22.660 318.3 32.4


6 PC138US, USLC-8

8. Precautions for disconnecting and con-necting hoses and tubes in air conditionercircuit1) Disconnection

k Collect the air conditioner refriger-ant (R134a) from the air condi-tioner circuit in advance.

a Ask professional traders for collectingand filling operation of refrigerant(R134a).

a Never release the refrigerant (R134a)to the atmosphere.

k If the refrigerant gas (R134a) getsin your eyes, you may lose yoursight. Accordingly, when collect-ing or filling it, you must be quali-fied for handling the refrigerantand put on protective goggles.

2) Connection1] When installing the air conditioner cir-

cuit hoses and tubes, take care thatdirt, dust, water, etc. will not enterthem.

2] When connecting the air conditionerhoses and tubes, check that O-rings(1) are fitted to their joints.

3] Check that each O-ring is not dam-aged or deteriorated.

4] When connecting the refrigerant pip-ing, apply compressor oil for refriger-ant (R134a) (DENSO: ND-OIL8,ZEXEL: ZXL100PG (equivalent toPAG46)) to its O-rings.

a Example of O-ring (Fitted to every joint ofhoses and tubes)

a For tightening torque, see the precautions forinstallation in each section of "Disassemblyand assembly".


PC138US, USLC-8 7

How to read the shop manual 1

1. Composition of shop manualThis shop manual contains the necessary technical information for services performed in a workshop.For ease of understanding, the manual is divided into the following sections.

00. Index and forewordThis section explains the shop manuals list, table of contents, safety, and basic information.

01. SpecificationThis section explains the specifications of the machine.

10. Structure, function and maintenance standardThis section explains the structure, function, and maintenance standard values of each component.The structure and function sub-section explains the structure and function of each component. Itserves not only to give an understanding of the structure, but also serves as reference material fortroubleshooting. The maintenance standard sub-section explains the criteria and remedies for dis-assembly and service.

20. Standard value tableThis section explains the standard values for new machine and judgement criteria for testing,adjusting, and troubleshooting. This standard value table is used to check the standard values intesting and adjusting and to judge parts in troubleshooting.

30. Testing and adjustingThis section explains measuring instruments and measuring methods for testing and adjusting, andmethod of adjusting each part. The standard values and judgement criteria for testing and adjustingare explained in Testing and adjusting.

40. TroubleshootingThis section explains how to find out failed parts and how to repair them. The troubleshooting isdivided by failure modes. The S mode of the troubleshooting related to the engine may be alsoexplained in the Chassis volume and Engine volume. In this case, see the Chassis volume.

50. Disassembly and assemblyThis section explains the special tools and procedures for removing, installing, disassembling, andassembling each component, as well as precautions for them. In addition, tightening torque andquantity and weight of coating material, oil, grease, and coolant necessary for the work are alsoexplained.

90. Diagrams and drawings (chassis volume)/Repair and replacement of parts (engine volume)q Chassis volume

This section gives hydraulic circuit diagrams and electrical circuit diagrams.q Engine volume

This section explains the method of reproducing, repairing, and replacing parts.

2. Revision and distributionAny additions, revisions, or other change of notices will be sent to KOMATSU distributors. Get the mostup-to-date information before you start any work.

q Some attachments and optional parts in this shop manual may not be delivered to certain areas. If oneof them is required, consult KOMATSU distributors.

q Materials and specifications are subject to change without notice.q Shop manuals are divided into the Chassis volume and Engine volume. For the engine unit, see the

engine volume of the engine model mounted on the machine.


8 PC138US, USLC-8

3. Filing methodFile by the brochures in the correct order of the form number printed in the shop manual compositiontable.

qqqq Revised edition markWhen a manual is revised, the ones and tens digits of the form number of each brochure isincreased by 1. (Example: 00, 01, 02 )

qqqq RevisionsRevised brochures are shown in the shop manual composition table.

4. SymbolsImportant safety and quality portions are marked with the following symbols so that the shop manual willbe used practically.

5. UnitsIn this shop manual, the units are indicated with International System of units (SI). For reference, con-ventionally used Gravitational System of units is indicated in parentheses { }.

Symbol Item Remarks

k Safety Special safety precautions are necessary when performing work.a Caution Special technical precautions or other precautions for preserving stan-dards are necessary when performing work.

4 Weight Weight of parts of component or parts. Caution necessary when selecting hoisting wire, or when working posture is important, etc.3 Tightening torque Places that require special attention for tightening torque during assembly.2 Coat Places to be coated with adhesives, etc. during assembly.

5 Oil, coolant Places where oil, etc. must be added, and capacity.

6 Drain Places where oil, etc. must be drained, and quantity to be drained.


PC138US, USLC-8 9

Explanation of terms for maintenance standard 1The maintenance standard values necessary for judgment of products and parts are described by the follow-ing terms.

1. Standard size and toleranceq To be accurate, the finishing size of parts

is a little different from one to another.q To specify a finishing size of a part, a tem-

porary standard size is set and an allow-able difference from that size is indicated.

q The above size set temporarily is calledthe standard size and the range of differ-ence from the standard size is called thetolerance.

q The tolerance with the symbols of + or isindicated on the right side of the standardsize.

a The tolerance may be indicated in the textand a table as [standard size (upper limitof tolerance/lower limit of tolerance)].Example) 120 (0.022/0.126)

q Usually, the size of a hole and the size ofthe shaft to be fitted to that hole are indi-cated by the same standard size and dif-ferent tolerances of the hole and shaft.The tightness of fit is decided by the toler-ance.

q Indication of size of rotating shaft and holeand relationship drawing of them

Example: Standard size Tolerance

120 0.0220.126

Example:

Standard sizeTolerance

Shaft Hole

60 0.0300.076+0.046+0


10 PC138US, USLC-8

2. Standard clearance and standard valueq The clearance made when new parts are

assembled is called the standard clear-ance, which is indicated by the rangefrom the minimum clearance to the maxi-mum clearance.

q When some parts are repaired, the clear-ance is generally adjusted to the standardclearance.

q A value of performance and function ofnew products or equivalent is called thestandard value, which is indicated by arange or a target value.

q When some parts are repaired, the valueof performance/function is set to the stan-dard value.

3. Standard interferenceq When the diameter of a hole of a part

shown in the given standard size and tol-erance table is smaller than that of themating shaft, the difference between thosediameters is called the interference.

q The range (A B) from the difference (A)between the minimum size of the shaftand the maximum size of the hole to thedifference (B) between the maximum sizeof the shaft and the minimum size of thehole is the standard interference.

q After repairing or replacing some parts,measure the size of their hole and shaftand check that the interference is in thestandard range.

4. Repair limit and allowable valueq The size of a part changes because of

wear and deformation while it is used. Thelimit of changed size is called the repairlimit.

q If a part is worn to the repair limit must bereplaced or repaired.

q The performance and function of a prod-uct lowers while it is used. A value belowwhich the product can be used withoutcausing a problem is called the allowablevalue.

q If a product is worn to the allowable value,it must be checked or repaired. Since thepermissible value is estimated from vari-ous tests or experiences in most cases,however, it must be judged after consider-ing the operating condition and customer'srequirement.

5. Clearance limitq Parts can be used until the clearance

between them is increased to a certainlimit. The limit at which those parts cannotbe used is called the clearance limit.

q If the clearance between the partsexceeds the clearance limit, they must bereplaced or repaired.

6. Interference limitq The allowable maximum interference

between the hole of a part and the shaft ofanother part to be assembled is called theinterference limit.

q The interference limit shows the repairlimit of the part of smaller tolerance.

q If the interference between the partsexceeds the interference limit, they mustbe replaced or repaired.


PC138US, USLC-8 11

Handling of electric equipment and hydraulic component 1To maintain the performance of the machine over a long period, and to prevent failures or other troublesbefore they occur, correct operation, maintenance and inspection, troubleshooting, and repairs mustbe carried out. This section deals particularly with correct repair procedures for mechatronics and is aimed atimproving the quality of repairs. For this purpose, it gives sections on Handling electric equipment andHandling hydraulic equipment (particularly gear oil and hydraulic oil).

Points to remember when handling electricequipment1. Handling wiring harnesses and connectors

Wiring harnesses consist of wiring connectingone component to another component, con-nectors used for connecting and disconnectingone wire from another wire, and protectors ortubes used for protecting the wiring.Compared with other electrical components fit-ted in boxes or cases, wiring harnesses aremore likely to be affected by the direct effectsof rain, water, heat, or vibration. Furthermore,during inspection and repair operations, theyare frequently removed and installed again, sothey are likely to suffer deformation or damage.For this reason, it is necessary to be extremelycareful when handling wiring harnesses.

2. Main failures occurring in wiring harness1) Defective contact of connectors (defec-

tive contact between male and female)Problems with defective contact are likelyto occur because the male connector isnot properly inserted into the female con-nector, or because one or both of the con-nectors is deformed or the position is notcorrectly aligned, or because there is cor-rosion or oxidization of the contact sur-faces. The corroded or oxidized contactsurfaces may become shiny again (andcontact may become normal) by connect-ing and disconnecting the connector about10 times.

2) Defective crimping or soldering of connec-torsThe pins of the male and female connec-tors are in contact at the crimped terminalor soldered portion, but if there is exces-sive force brought to bear on the wiring,the plating at the joint will peel and causeimproper connection or breakage.


12 PC138US, USLC-8

3) Disconnections in wiringIf the wiring is held and the connectors arepulled apart, or components are lifted witha crane with the wiring still connected, or aheavy object hits the wiring, the crimpingof the connector may separate, or the sol-dering may be damaged, or the wiringmay be broken.

4) High-pressure water entering connectorThe connector is designed to make it diffi-cult for water to enter (drip-proof struc-ture), but if high-pressure water is sprayeddirectly on the connector, water may enterthe connector, depending on the directionof the water jet. Accordingly, take care notto splash water over the connector. Theconnector is designed to prevent waterfrom entering, but at the same time, ifwater does enter, it is difficult for it to bedrained. Therefore, if water should get intothe connector, the pins will be short-cir-cuited by the water, so if any water gets in,immediately dry the connector or takeother appropriate action before passingelectricity through it.

5) Oil or dirt stuck to connectorIf oil or grease are stuck to the connectorand an oil film is formed on the mating sur-face between the male and female pins,the oil will not let the electricity pass, sothere will be defective contact. If there isoil or grease stuck to the connector, wipe itoff with a dry cloth or blow it dry with com-pressed air and spray it with a contactrestorer.a When wiping the mating portion of the

connector, be careful not to useexcessive force or deform the pins.

a If there is oil or water in the com-pressed air, the contacts will becomeeven dirtier, so remove the oil andwater from the compressed air com-pletely before cleaning with com-pressed air.


PC138US, USLC-8 13

3. Removing, installing, and drying connec-tors and wiring harnesses1) Disconnecting connectors

1] Hold the connectors when discon-necting.When disconnecting the connectors,hold the connectors. For connectorsheld by a screw, loosen the screwfully, then hold the male and femaleconnectors in each hand and pullapart. For connectors which have alock stopper, press down the stopperwith your thumb and pull the connec-tors apart.a Never pull with one hand.

2] When removing from clipsq Both of the connector and clip have

stoppers, which are engaged witheach other when the connector isinstalled.

q When removing a connector from aclip, pull the connector in a paralleldirection to the clip for removing stop-pers.a If the connector is twisted up and

down or to the left or right, thehousing may break.

3] Action to take after removing connec-torsAfter removing any connector, cover itwith a vinyl bag to prevent any dust,dirt, oil, or water from getting in theconnector portion.a If the machine is left disassem-

bled for a long time, it is particu-larly easy for improper contact tooccur, so always cover the con-nector.


14 PC138US, USLC-8

2) Connecting connectors1] Check the connector visually.

Check that there is no oil, dirt, orwater stuck to the connector pins(mating portion).Check that there is no deformation,defective contact, corrosion, or dam-age to the connector pins.Check that there is no damage orbreakage to the outside of the con-nector.a If there is any oil, water, or dirt

stuck to the connector, wipe it offwith a dry cloth. If any water hasgot inside the connector, warmthe inside of the wiring with adryer, but be careful not to makeit too hot as this will cause shortcircuits.

a If there is any damage or break-age, replace the connector.

2] Fix the connector securely.Align the position of the connectorcorrectly, and then insert it securely.For connectors with the lock stopper,push in the connector until the stop-per clicks into position.

3] Correct any protrusion of the boot andany misalignment of the wiring har-ness.For connectors fitted with boots, cor-rect any protrusion of the boot. Inaddition, if the wiring harness is mis-aligned, or the clamp is out of posi-tion, adjust it to its correct position.a If the connector cannot be cor-

rected easily, remove the clampand adjust the position.

q If the connector clamp has beenremoved, be sure to return it toits original position. Check alsothat there are no loose clamps.


PC138US, USLC-8 15

3) Heavy duty wire connector (DT 8-pole, 12-pole)Disconnection (Left of figure)

While pressing both sides of locks (a)and (b), pull out female connector (2).

Connection (Right of figure)1] Push in female connector (2) horizon-

tally until the lock clicks.Arrow: 1)

2] Since locks (a) and (b) may not be setcompletely, push in female connector(2) while moving it up and down untilthe locks are set normally.Arrow: 1), 2), 3)a Right of figure: Lock (a) is pulled

down (not set completely) andlock (b) is set completely.

(1): Male connector(2): Female connector(a), (b): Locks

q Disconnection q Connection (Example ofincomplete setting of (a))


16 PC138US, USLC-8

4) Drying wiring harnessIf there is any oil or dirt on the wiring har-ness, wipe it off with a dry cloth. Avoidwashing it in water or using steam. If theconnector must be washed in water, donot use high-pressure water or steamdirectly on the wiring harness. If watergets directly on the connector, do as fol-lows.1] Disconnect the connector and wipe

off the water with a dry cloth.a If the connector is blown dry with

compressed air, there is the riskthat oil in the air may causedefective contact, so remove alloi l and water from the com-pressed air before blowing withair.

2] Dry the inside of the connector with adryer.If water gets inside the connector, usea dryer to dry the connector.a Hot air from the dryer can be

used, but regulate the time thatthe hot air is used in order not tomake the connector or relatedparts too hot, as this will causedeformation or damage to theconnector.

3] Carry out a continuity test on the con-nector.After drying, leave the wiring harnessdisconnected and carry out a continu-ity test to check for any short circuitsbetween pins caused by water.a After completely drying the con-

nector, b low i t wi th contactrestorer and reassemble.


PC138US, USLC-8 17

4. Handling controller1) The controller contains a microcomputer

and electronic control circuits. These con-trol all of the electronic circuits on themachine, so be extremely careful whenhandling the controller.

2) Do not place objects on top of the control-ler.

3) Cover the control connectors with tape ora vinyl bag. Never touch the connectorcontacts with your hand.

4) During rainy weather, do not leave thecontroller in a place where it is exposed torain.

5) Do not place the controller on oil, water, orsoil, or in any hot place, even for a shorttime. (Place it on a suitable dry stand).

6) Precautions when carrying out arc weldingWhen carrying out arc welding on thebody, disconnect all wiring harness con-nectors connected to the controller. Fit anarc welding ground close to the weldingpoint.

5. Points to remember when troubleshootingelectric circuits1) Always turn the power OFF before discon-

necting or connecting connectors.2) Before carrying out troubleshooting, check

that all the related connectors are properlyinserted.a Disconnect and connect the related

connectors several times to check.3) Always connect any disconnected con-

nectors before going on to the next step.a If the power is turned ON with the

connectors still disconnected, unnec-essary abnormality displays will begenerated.

4) When carrying out troubleshooting of cir-cuits (measuring the voltage, resistance,continuity, or current), move the relatedwiring and connectors several times andcheck that there is no change in the read-ing of the tester.a If there is any change, there is proba-

bly defective contact in that circuit.


18 PC138US, USLC-8

Points to remember when handling hydraulic equipmentWith the increase in pressure and precision of hydraulic equipment, the most common cause of failure is dirt(foreign material) in the hydraulic circuit. When adding hydraulic oil, or when disassembling or assemblinghydraulic equipment, it is necessary to be particularly careful.

1. Be careful of the operating environment.Avoid adding hydraulic oil, replacing filters, orrepairing the machine in rain or high winds, orplaces where there is a lot of dust.

2. Disassembly and maintenance work in thefieldIf disassembly or maintenance work is carriedout on hydraulic equipment in the field, there isdanger of dust entering the equipment. It isalso difficult to check the performance afterrepairs, so it is desirable to use unit exchange.Disassembly and maintenance of hydraulicequipment should be carried out in a speciallyprepared dustproof workshop, and the perfor-mance should be checked with special testequipment.

3. Sealing openingsAfter any piping or equipment is removed, theopenings should be sealed with caps, tapes, orvinyl bags to prevent any dirt or dust fromentering. If the opening is left open or isblocked with a rag, there is danger of dirtentering or of the surrounding area beingmade dirty by leaking oil so never do this. Donot simply drain oil out onto the ground, butcollect it and ask the customer to dispose of it,or take it back with you for disposal.

4. Do not let any dirt or dust get in duringrefilling operationsBe careful not to let any dirt or dust get in whenrefilling with hydraulic oil. Always keep the oilfiller and the area around it clean, and also useclean pumps and oil containers. If an oil clean-ing device is used, it is possible to filter out thedirt that has collected during storage, so this isan even more effective method.


PC138US, USLC-8 19

5. Change hydraulic oil when the temperatureis highWhen hydraulic oil or other oil is warm, it flowseasily. In addition, the sludge can also bedrained out easily from the circuit together withthe oil, so it is best to change the oil when it isstill warm. When changing the oil, as much aspossible of the old hydraulic oil must bedrained out. (Drain the oil from the hydraulictank; also drain the oil from the filter and fromthe drain plug in the circuit.) If any old oil is left,the contaminants and sludge in it will mix withthe new oil and will shorten the life of thehydraulic oil.

6. Flushing operationsAfter disassembling and assembling the equip-ment, or changing the oil, use flushing oil toremove the contaminants, sludge, and old oilfrom the hydraulic circuit. Normally, flushing iscarried out twice: primary flushing is carriedout with flushing oil, and secondary flushing iscarried out with the specified hydraulic oil.

7. Cleaning operationsAfter repairing the hydraulic equipment (pump,control valve, etc.) or when running themachine, carry out oil cleaning to remove thesludge or contaminants in the hydraulic oil cir-cuit. The oil cleaning equipment is used toremove the ultra fine (about 3 m) particles thatthe filter built in the hydraulic equipment can-not remove, so it is an extremely effectivedevice.


20 PC138US, USLC-8

Handling of connectors newly used for engines 1a Mainly, following engines are object for follow-

ing connectors.q 107E-1q 114E-3q 125E-5q 140E-5q 170E-5q 12V140E-3

1. Slide lock type(FRAMATOME-3, FRAMATOME-2)q 107 170, 12V140 engines

q Various pressure sensors and NEspeed sensor

Examples)Intake air pressure in intake manifold:PIM (125, 170, 12V140 engines)Oil pressure sensor: POIL

(125, 170, 12V140 engines)Oil pressure switch

(107, 114 engines)Ne speed sensor of flywheel housing:NE (107 170, 12V140 engines)Ambient pressure sensor: PAMB

(125, 170, 12V140 engines)

Disconnect connector (1) according to the fol-lowing procedure.1) Slide lock (L1) to the right.2) While pressing lock (L2), pull out connec-

tor (1) toward you.a Even if lock (L2) is pressed, connec-

tor (1) cannot be pulled out towardyou, if part A does not float. In thiscase, float part A with a small screw-driver while press lock (L2), and thenpull out connector (1) toward you.

2. Pull lock type (PACKARD-2)q 107 170, 12V140 engine

q Various temperature sensorsExample)

Intake air temperature sensor inintake manifold: TIMFuel temperature sensor: TFUELOil temperature sensor: TOILCoolant temperature sensor: TWTR,etc.

Disconnect the connector by pulling lock(B) (on the wiring harness side) of connec-tor (2) outward.


PC138US, USLC-8 21

3. Push lock typeq 107, 114 engines

Example)Fuel pressure sensor in common rail(BOSCH-03)

Disconnect connector (3) according to the fol-lowing procedure.1) While pressing lock (C), pull out connector

(3) in the direction of the arrow.

q 114 engine

q 107 engine

a If the lock is on the underside, useflat-head screwdriver [1] since youcannot insert your fingers.

2) While pressing up lock (C) of the connec-tor with flat-head screwdriver [1], pull outconnector (3) in the direction of the arrow.

q 107, 114 engineExample) Intake air pressure/temperature sensor inintake manifold (SUMITOMO-04)

3) While pressing lock (D), pull out connector(4) in the direction of the arrow.


22 PC138US, USLC-8

q 125 170, 12V140 engine4) While pressing lock (E) of the connector,

pullout connector (5) in the direction of thearrow.

Example)Fuel pressure in common rail: PFUEL etc.(AMP-3)

Example)Injection pressure control valve of fuelsupply pump: PCV (SUMITOMO-2)

Example)Speed sensor of fuel supply pump: G (SUMITOMO-3)a Pull the connector straight up.

4. Turn-housing type (Round green connector)q 140 engine

Example)Intake air pressure sensor in intake mani-fold (CANNON-04): PIM etc.

1) Disconnect connector (6) according to thefollowing procedure.1] Turn housing (H1) in the direction of

the arrow.a When connector is unlocked,

housing (H1) becomes heavy toturn.

2] Pull out housing (H1) in the directionof the arrow.

a Housing (H1) is left on the wiring har-ness side.

2) Connect the connector according to thefollowing procedure.1] Insert the connector to the end, while

setting its groove.2] Turn housing (H1) in the direction of

the arrow until it clicks.


PC138US, USLC-8 23

How to read electric wire code 1a The information about the wires unique to each machine model is described in Troubleshooting section,

Relational information of troubleshooting.

In the electric circuit diagram, the material, thickness, and color of each electric wire are indicated by sym-bols. The electric wire code is helpful in understanding the electric circuit diagram.

1. Type, symbol, and materialAV and AVS are different in only thickness and outside diameter of the cover. AEX is similar to AV inthickness and outside diameter of AEX and different from AV and AVS in material of the cover.

Example: AEX 0.85 L - - - Indicates blue, heat-resistant, low-voltage wire for automobile, having nomi-nal No. of 0.85Indicates color of wire by color code.Color codes are shown in Table 3.

Indicates size of wire by nominal No.Size (Nominal No.) is shown in Table 2.

Indicates type of wire by symbol.Type, symbol, and material of wire are shown in Table 1.(Since AV and AVS are classified by size (nominal No.), they are not indi-cated.)

(Table 1)

Type Sym-bol MaterialUsing

temperature range (C)

Example of use

Low-voltage wire for

automobileAV

Conduc-tor

Annealed copper for elec-tric appliance

30 to +60

General wiring (Nominal No. 5 and above)

Insulator Soft polyvinyl chlorideThin-cover low-voltage

wire for automobile

AVS

Conduc-tor

Annealed copper for elec-tric appliance General wiring

(Nominal No. 3 and below)Insulator Soft polyvinyl chloride

Heat-resis-tant low-volt-age wire for automobile

AEX

Conduc-tor

Annealed copper for elec-tric appliance

50 to +110General wiring in extremely

cold district, wiring at high-tem-perature placeInsulator Heat-resistant crosslinked polyethylene


24 PC138US, USLC-8

2. Dimensions

f of nominal No. denotes flexible.

(Table 2)Nominal No. 0.5f (0.5) 0.75f (0.85) 1.25f (1.25) 2f 2 3f 3 5

Conductor

Number of strands/Diam-eter of strand

20/0.18 7/0.32 30/0.18 11/0.32 50/0.18 16/0.32 37/0.26 26/0.32 58/0.26 41/0.32 65/0.32

Sectional area (mm2) 0.51 0.56 0.76 0.88 1

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