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 four answer choices. To pass, the applicant must answer at least 20 questions correctly. Test questions come from the West Virginia Commercial Driver’s 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

1. Failing to drain the tanks in an air brake system can result in:

Water freezing and causing brake failure.

Squishy brakes.

Too much air collecting.

Too much fuel being carried.

In an air brake system, the air storage tanks must be drained to remove accumulated water and compressor oil. Failing to do this can cause damage. For example, water that has built up in the system could freeze in cold weather and cause brake failure.

2. To confirm that a trailer has ABS, you can:

Look under the trailer for wheel speed sensors coming from the back of the brakes.

Look under the hood for the ABS sticker.

Look at the tires.

Remove a tire and look for the ABS sensor on the axle.

If you are unsure if a trailer is equipped with an Anti-Lock Braking System (ABS), look under the vehicle for the electronic control unit and wheel speed sensor wires coming from the back of the brakes.

3. If the low pressure warning light comes on while you are driving:

Braking will only occur if there is enough air in the tanks.

You can brake 14 times before the air in the system runs out.

You should continue to drive normally and check the brake system when it is convenient.

You should continue driving, but turn the emergency flashers on to warn other motorists.

If the low air pressure warning light turns on, you should stop and safely park your vehicle as soon as possible. Controlled braking will be possible only as long as enough air remains in the tanks.

4. The brake pedal is part of which braking system?

The service brake system

The parking brake system

The emergency brake system

The auxiliary brake system

The service brake system applies and releases the brakes when a driver presses the brake pedal while driving normally.

5. In a dual air brake system, a leak in one system:

Always means there are leaks in both systems.

May not affect the other system.

Is not something to worry about.

Will also affect the other system.

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.

6. On newer vehicles, how do you put on the parking brake?

Move a lever to the right.

Push in the yellow, diamond-shaped knob.

Pull out the yellow, diamond-shaped knob.

Pull up on the steering column.

On newer vehicles with air brakes, the parking brake is controlled by a yellow, diamond-shaped knob. The knob is pulled out to set the brakes, and pushed in to release them.

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