Air Brakes

This endorsement is required for driving a vehicle with air brakes. To receive this endorsement, applicants must pass a test. The test consists of 25 multiple choice.. Read More

This endorsement is required for driving a vehicle with air brakes. To receive this endorsement, applicants must pass a 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 New York State Commercial Motor Vehicle Drivers Handbook. Questions come from chapters covering: Air Brakes. The Air Brakes endorsement may be used with the Class A, B or C CDL.

Number of Question
Passing Score

19. 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.

20. To inspect slack adjusters on S-cam brakes, you need to:

Explanation
Check each slack adjuster after parking on level ground, setting wheel chocks, and disengaging the parking brake. Pull the slack adjusters to make sure they do not move more than about one inch from where the push rod is attached. If they move more than one inch, they may be out of adjustment and will need to be fixed.

21. On a truck with air brakes, the braking system’s air compressor:

Explanation
In an air brake system, the air compressor pumps air into the air storage tanks. The air compressor is controlled by the air compressor governor.

22. How many air storage tanks are used in an air brake system?

Explanation
Air storage tanks are used to hold compressed air. The number and size of air tanks in an air brake system varies among vehicles.

23. When using the controlled braking method in an emergency situation, you should:

Explanation
The controlled braking method for emergency stops involves applying the brakes as hard as you can without locking the wheels. Keep steering wheel movements small when braking in this way.

24. Test the low pressure warning signal:

Explanation
It is essential that your low pressure warning light function properly. After allowing the system to charge, you can test the warning signal by rapidly applying and releasing the brake pedal. This will release air from the braking system and the warning signal should come on when pressure drops to a dangerous level.

25. Before starting down a hill, be sure to:

Explanation
Before starting down a hill, be sure to switch into a low gear. Gravity will increase your vehicle's speed as you travel downhill.
DMV Writen Test