Instructions

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. Each question has three or four answer choices. To pass, the applicant must answer at least 20 questions correctly. Test questions come from the Alabama 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 25

Passing Score 20

7. The ____ between an air compressor and reservoir tank prevents air from escaping if the air compressor has a leak.

Slack adjuster

One-way check valve

Tractor protection valve

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.

8. When parked on a flat surface, you should:

Use wheel chocks to prevent your vehicle from moving.

Not use wheel chocks.

Use wheel chocks, but only if you have applied the parking brake.

When parking on a level surface, you should use wheel chocks. If the vehicle is not equipped with spring brakes, this is essential to prevent the trailer from moving.

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

You will be unable to move the vehicle.

A separate air tank can be used to release the spring brakes for a short period of time.

You can use the spring brakes to continue driving normally.

The air tanks will automatically refill to a safe air pressure level.

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.

10. Having ABS on only one axle:

Can be dangerous.

Still allows you additional control when braking.

Slows the vehicle, but cannot stop it.

If you have an Anti-Lock Braking System (ABS) equipped on only the tractor, only the trailer, or only one axle, you will still have more control over the vehicle when braking than you would without ABS. You should brake normally.

11. If your tractor is equipped with ABS but your trailer is not, the ABS:

Will not be effective.

Will still improve your steering control.

Will make jackknifing easier.

Will allow others to see when you brake.

In a tractor-trailer combination, if the tractor is equipped with an Anti-Lock Braking System (ABS) but the trailer is not, the ABS will still improve the driver's steering control. The driver should keep an eye on the trailer and let up on the brakes if the trailer begins to swing out.

12. In a vehicle with dual air brakes, a leak in one system ____ the second system.

Will always affect

May not affect

Is caused by

A dual air brake system is made up of two separate air brake systems. If there is an air leak in one system, it may not affect the other.

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