Which task is NOT performed during the tractor protection valve test?
Answer: C
Accelerating to 5 mph and then applying the brakes
Once the air brake pressure is up to operating pressure, turn off the ignition. Pump the service brake to vent air to the atmosphere, the tractor protection valve should activate when pressure reaches 20 to 45 psi.
All choices
- ATurning off the ignition.
- BVenting air to the atmosphere by applying and releasing the brake pedal.
- CAccelerating to 5 mph and then applying the brakes
Why the other answers are wrong
A. Turning off the ignition.
Turning off the ignition is part of the tractor protection valve test procedure.
B. Venting air to the atmosphere by applying and releasing the brake pedal.
Venting air by applying and releasing the brake pedal is required during the test.
CDL Combination Vehicles Test Info
Questions on Exam
20
Passing Score
80%
Time Limit
Typically 30 minutes; varies by testing location
The Combination Vehicles test content is federally standardized, so this question applies in every state. Age limits, fees, and testing procedures do vary — check your state's CDL requirements.
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