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.. Read More

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

7. Brakes may get out of adjustment:

Explanation
Brakes can get out of adjustment quickly, especially if they are used to the point of overheating. Brake adjustment should be checked frequently.

8. In a vehicle with dual parking control valves, once air pressure is lost and the spring brakes come on:

Explanation
In a vehicle with dual parking control valves, there is a separate air tank that can be used to temporarily release the spring brakes if they have been activated due to low air pressure. Pushing in the proper control will release the spring brakes for a short period of time, allowing the driver to move the vehicle in an emergency.

9. When traveling down a steep downgrade, the best way to use your brakes is to:

Explanation
On a long or steep downgrade, brakes should only be used to supplement the braking effect of the engine. Apply the brakes just enough to feel a definite slowing down, then release them once you are about 5 mph below your target "safe" speed. Once your vehicle reaches its safe speed again, repeat this process.

10. 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.

11. Service brakes should:

Explanation
Before driving, you should always verify that your service brakes are in good working order. Testing the brakes before a trip allows you to locate any problems before you need to brake while on the road.

12. 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.
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