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 three or four answer choices. To pass, the applicant must answer at least 20 questions correctly. Test questions come from the Maryland Commercial Driver Guide. 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
1. When parking, you should not use the parking brake if:
Explanation
If your brakes are hot after coming down a steep grade, you should not use your parking brake when parking. Let your brakes cool before applying the parking brake or risk damaging the brakes.
2. During an applied leakage test, the maximum leakage rate for a triple combination vehicle is:
Explanation
It is important to know the maximum air loss rate that is safe for your specific vehicle. A triple combination should have a leakage rate no higher than 6 psi in a minute during an applied leakage test.
3. To stop in a vehicle that uses air brakes, the driver should:
Explanation
To make a normal stop in a vehicle with air brakes, push the brake pedal down. The harder the pedal is pressed, the more air pressure is released.
4. A low air pressure warning signal:
Explanation
Any vehicle with air brakes must be equipped with a low air pressure warning signal.
5. What does the air compressor governor do?
Explanation
In an air brake system, the air compressor governor controls when the air compressor pumps air into the air storage tanks.
6. When parked on a flat surface, you should:
Explanation
