1 mechanics of a school bus 2010—11 driver trainer inservice1

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Mechanics

of a

School Bus

2010—11 Driver Trainer Inservice 1

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MECHANICS of a

SCHOOL BUS

• Overview– Conducting Pre-Trip & Post-Trip

Inspections.– Differences between buses.– Reporting mechanical defects.– New emission controls devices.

2010—11 Driver Trainer Inservice

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PRE-TRIP INSPECTIONS

• Transportation—Operation Rules

Pre and Post Trip Requirements.

–WAC 392-145-041(2)

–WAC 392-145-041(5)

• Other state recommended items.


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1. Approach the bus.

• Look for vehicle problems.

• Check for fluids on the ground.

• Check for hoses or wires hanging.


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2. Insert key.

–Check engine compartment.

• Coolant

• Engine Oil

• Power Steering Fluid etc.


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3. Check Suspension.

• Brake Condition.

• Wheel Condition.

• Rim Condition.


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4. Start your Bus.

• Check and Read Gauges/Warning Buzzers.

• Check lights, oil pressure gauge, voltmeter, etc.


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PRE-TRIP INSPECTIONS5. Check Outside of Bus.• Right Side.

Glass/BodyRight Emergency DoorAir tank if on this sideLights/Emergency Exit

• Rear.LightsEmergency Door



5. Check Outside of Bus (continued)• Left.

Glass/BodyLeft Emergency DoorAir tank – if on this sideStop Sign Operation/Damage

• Front.All Lights


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6. Check Bus Interior– Steps, aisles, seats for damage.– Side, top, and rear emergency doors.– First aid kit.– Reflectors.– Spare fuses.– Fire extinguisher.– Body fluid clean-up kit.


REPORT DEFECTS

Proper Pre-trip Means Proper Documentation.

• Clear.• Clean.• Legible.• Accurate.• Informative.



KISS:

Keep It Short and Simple Write clear, short explanations using key

words to explain what you want to convey.

REPORT DEFECTS


REPORT SYMPTOMS,NOT ASSUMPTIONS

Report what you √ See. √ Smell. √ Hear.√ Not what you assume.

REPORT DEFECTS


LOOK AHEAD Look for pre-breakdown defects:

• Dampness around hoses.

• Shiny spots.

• Loose clamps.

• Air gauges not reading equally.

REPORT DEFECTS


Improper: My bus is dead, I need a spare.

Alternative: My bus will not restart at the school, it turns over but will not fire or start.

REPORT DEFECTS

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Never omit written report

• Inspect actual problem.

• Document clearly, describing specific symptoms.

REPORT DEFECTS

Information

can be

Misinterpreted


REPORT DEFECTS

Know what to do…

Know when to continue


REPORT DEFECTS

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KNOW WHEN TO CONTINUE

Example: Anti-lock light comes on,

• Braking system will continue operating.

• Safe to continue with proper documentation and reporting.

REPORT DEFECTS


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Example: Low air warning,• Warning comes on at 58 psi during

inspection. • Bus is drivable, but report immediately. • Legal down to 55 psi by WSP inspection

standards.

REPORT DEFECTS


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Example: Coolant leaks,• Can leak be isolated by shutting off

heater hose valves? • How much coolant lost? • Risk of contamination to students or

damage to bus?

REPORT DEFECTS


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Example: Brake/tail/turn light not working,

• Buses may be legally driven if at least one turn/brake light operational on any corner of the vehicle.

• Follow your district’s policy.

REPORT DEFECTS


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Example: Cracked engine belts,

• Small cracks are found on inside grooves of engine belts.

• The belt may be usable for a long time. • Some cracking is normal. • Have your maintenance personnel check

and review what is acceptable.

REPORT DEFECTS


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WAC 392-145-031(2)

• School bus drivers shall immediately report any suspected malfunction or needed repair of the school bus in their charge.

REPORT DEFECTS


DIFFERENCES IN EQUIPMENTBus Interior

• Type of Bus.

• Control Location, i.e., Dash Side panel Overhead Steering wheel



• Brake and accelerator pedals Location, height, distance



• 8-way sequencing system, 2 or 3 switch controls.

• Seat and steering column adjustments.

• Wiper control location.

• Gauge cycling upon start-up.

• Chain box.



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• Locate noise suppression switch.

• Strobe switch—overhead/intensity.

• Child Check—electronic child monitor.

• Winter equipment—chains, sanders, retarders.



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Familiarize yourself before taking a bus.

Utilize: • Dispatcher.• Trainer.• Mechanic.



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Industry is required to reduce emissions.

• Harmful gasses, and • Particulates are reduced by

the new technology on our buses.

EMISSION CONTROLS

Why are we concerned? • Effects on children’s health. • Detrimental to environment.• Changes fuel use that affects,

– Mileage– Bus operation– Maintenance of equipment


EMISSION CONTROLS

EMISSION CONTROLS

Past and Present

1994 – 2007Gasses Reduced 67%As of 2007 particulates reduced by 90%.

2010 EPA now requires 83% reduction in NOx.



EMISSION CONTROLS


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DOC—Diesel Oxidation Catalyst

• A muffler shaped device with a ceramic center.– Collects an extreme amount of heat

from the engine exhaust system. – Burns unused gases.

EMISSION CONTROLS


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EGR—Exhaust Gas Recirculation

• A process of rerouting exhaust gases through the engine

• More thoroughly burns unused fuel and gases

EMISSION CONTROLS

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SCR—Selective Catalytic Reduction

• Generally used in combination with EGR to reduce NOx gases.

• Utilizes an additional chemical to change the compound of gases in a catalyst.


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EMISSION CONTROLS


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DEF—Diesel Exhaust Fluid

• A chemical additive injected into the exhaust flow of a DOC or SCR catalyst.

• Changes gases into ammonia that when heated changes again into nitrogen and water.

EMISSION CONTROLS


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Regeneration System

• Incorporates a particulate trap in the exhaust system, and

• Regenerates or cleans by means of computer control.

EMISSION CONTROLS


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Crankcase Particulate Filtration System• A fume collecting canister connected to

the engine breathing apparatus.• Separates large, mostly oil particulates

by means of a filter and holding canister.• Gases return to the engine to be re-

burned.

EMISSION CONTROLS


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Summary1. Pre-Trip:

–Conduct a thorough pre-trip.

• Know what items you should check.

• Check State requirements and recommendations.

• Follow district required pre-trip.

2. Document and Report Defects.

• Keep it Short and Simple (KISS).

• Be accurate and clear.

• Report immediately.

• Know if you can continue on.


Summary

3. Understand differences in equipment:

• Controls/Gauges.

• Pedals.

• Gauges.

• Winter Equipment.Familiarize yourself with

location and operation


Summary


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4. Emission Control Devices:

• Emission controls are an integral part of our school buses.

• EPA has strict requirements that reduce gas and particulate levels.

• Report concerns and learn about how your equipment should operate.

Summary


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EVALUATION

1. What items require checking during a pre-trip?

2. What items operate differently on buses in your fleet?

3. What is included in a proper report of faulty items?

4. Name three bus emission control devices.

1 mechanics of a school bus 2010—11 driver trainer inservice1

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