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 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. Most heavy-duty vehicles use:
Explanation
Most heavy-duty vehicles use dual air brake systems. A dual system has two separate air brake systems with a single set of controls.
8. What color is the low air pressure warning light?
Explanation
A low air pressure warning signal is required in vehicles with air brakes. The warning light is usually red and may be accompanied by a buzzer.
9. An Anti-Lock Braking System (ABS):
Explanation
Anti-Lock Braking Systems (ABS) are compatible with air braking systems. ABS helps maintain control of a vehicle and prevents the wheels from locking up during hard braking on slippery surfaces. ABS can still provide benefits even if is present on only one axle.
10. What do anti-lock brakes do?
Explanation
The function of an Anti-Lock Braking System (ABS) is to prevent the vehicle's wheels from locking up from hard brake application.
11. If the air pressure warning light comes on, you should:
Explanation
If the low air pressure warning signals activate, it is essential that you bring the vehicle to a safe stop while you are still able to control the brakes.
12. In a newer vehicle, you apply the parking brake:
Explanation
