Practical Skills and Training Flashcards

During a DOT annual vehicle inspection, a technician finds a cracked windshield with a star break of 3/4 inch in the driver's critical viewing area. This vehicle should be:

Answer: Failed and placed out of service until repaired

FMCSA defines any crack, star break, or discoloration in the driver's critical viewing area as a defect that places the vehicle out of service.

When performing a cooling system pressure test on a heavy-duty diesel engine, the system should be pressurized to:

Answer: The pressure rating stamped on the radiator cap

The system is pressurized to the radiator cap's rated pressure to detect leaks without over-pressurizing and damaging soft components.

A coach technician is replacing fuel filters on a common rail diesel. After installation, the correct bleeding procedure is to:

Answer: Use a hand primer pump to fill the filters before cranking

Hand-priming the fuel filters before cranking prevents dry starts that can damage the high-pressure pump and ensures rapid, damage-free startup.

When using a chassis dynamometer to verify a road-speed-governor setting on a coach, the technician must ensure:

Answer: Only the rear drive axle is on rollers and the parking brake is released

For a single-rear-axle coach, only the drive axle rolls on the dynamometer; the parking brake must be released so the brakes don't mask the actual governed speed.

A technician is torquing cylinder head bolts on a diesel engine that specifies angle torque. After reaching the initial torque value, the angle torque step requires:

Answer: Rotating each bolt a specified number of degrees using an angle meter or template

Angle torque (torque-to-yield) requires rotating each bolt a precise number of degrees beyond the initial clamp load, measured with a click-style angle adapter or protractor.

When inspecting a coach for proper emergency exit door operation, federal standards require that each emergency door:

Answer: Opens from both inside and outside without special tools or knowledge

FMCSA and FMVSS require emergency exits to be operable from both the interior and exterior without special tools or knowledge so occupants and rescuers can escape quickly.

During a scheduled PM, a technician measures fan hub bearing play and finds axial movement of 0.025 inch. The correct action is to:

Answer: Replace the fan hub assembly

Fan hub bearings with measurable axial play typically indicate worn or failed bearings that cannot be readjusted; the hub assembly should be replaced to prevent catastrophic fan failure.