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 answer choices. To pass, the applicant must answer at least 20 questions correctly. Test questions come from the Virginia Commercial Driver 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
7. If you are driving and the ABS light comes on, it means that the ABS:
Explanation
ABS malfunction lamps indicate that something in the Anti-Lock Braking System is not working properly.
8. ABS brakes:
Explanation
The purpose of an Anti-Lock Braking System (ABS) is to prevent a vehicle's wheels from locking up when the driver brakes hard on a slippery surface.
9. Air brakes use ____ to function.
Explanation
The brakes in an air brake system use compressed air to function properly.
10. The ____ between an air compressor and reservoir tank prevents air from escaping if the air compressor has a leak.
Explanation
A one-way check valve is required to be between an air compressor and the first main reservoir. This valve prevents air from escaping the system if the air compressor develops a leak.
11. If the spring brakes are on, you should:
Explanation
Do not use the brake pedal when the spring brakes are on. This could damage the brakes by subjecting them to the combined forces of springs and air pressure.
12. What tells you how much pressure is in your vehicle's air tanks?
Explanation
