Air Brakes
This endorsement is required for driving a vehicle with air brakes. To receive this endorsement, applicants must pass a written test. The test consists of 25 multiple choice questions. Each question has four answer choices. To pass, the applicant must answer at least 20 questions correctly. Test questions come from the West Virginia Commercial Driver’s License Manual. Questions come from the chapter covering: Air Brakes. The Air Brakes endorsement may be used with the Class A, B or C CDL.
Number of Question
Passing Score
13. Truck tractors with air brakes that were built on or after March 1, 1997 are equipped with:
Explanation
Truck tractors with air brakes that were manufactured on or after March 1, 1997 are required to be equipped with Anti-Lock Braking Systems (ABS). ABS is required in any other type of vehicle with air brakes that was manufactured on or after March 1, 1998.
14. If the air pressure warning light comes on, you should:
Explanation
If the air pressure warning light or buzzer comes on while you are driving, you should immediately stop and safely park the vehicle. This warning signal indicates that there is a problem in the air brake system that needs to be fixed.
15. Vehicles with dual air brake systems:
Explanation
Before driving a vehicle with a dual air brake system, you must allow the air compressor time to build up at least 100 psi of air pressure in both the primary and secondary systems.
16. Which part of the truck is the air compressor connected to?
Explanation
In an air brake system, the air compressor is connected to the engine through gears or a v-belt.
17. Pressing and releasing a brake pedal unnecessarily can:
Explanation
In an air brake system, pressing and releasing the brake pedal unnecessarily can release air from the braking system faster than the compressor can replace it.
18. What does the air compressor governor do?
Explanation
