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. To pass, the applicant must answer at least 20 questions correctly. Test questions come from the Commonwealth of Pennsylvania Commercial Driver’s Manual. 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. 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.
20. How should you test the low pressure warning signal?
Explanation
It is essential that your low pressure warning light functions 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.
21. While driving downhill, you should brake until you reach a speed that is ____ below your safe speed, then release the brake pedal.
Explanation
While driving downhill, you should hold down the brake pedal until your vehicle reaches a speed 5 mph below your safe speed, then release the brake pedal. Repeat this process.
22. A tank endorsement is:
Explanation
In general, a tank endorsement is required to a drive tank vehicle used to transport liquids or gases. This applies to both hazardous and non-hazardous materials.
23. 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.
24. When you need to stop in an emergency, you should:
Explanation
If you need to make an emergency stop, you can use either the controlled braking method or the stab braking method. It's important to brake in a way that keeps your vehicle traveling in a straight line while still allowing you to turn, if necessary.
25. When you press the brake pedal in a vehicle with S-cam brakes, air pressure pushes out the rod and moves the:
Explanation
