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. To pass, the applicant must answer at least 20 questions correctly. Test questions come from the Georgia Commercial Driver’s Manual. Questions come from 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. On trucks and buses, where are ABS malfunction lamps located?

On the driver’s door

On the instrument panel

On the outside of the vehicle by the passenger’s door

Under the hood

Tractors, trucks, and buses with Anti-Lock Braking Systems (ABS) have yellow malfunction lamps located on their instrument panels. Trailers have yellow ABS malfunction lamps on their left side, either on the front or rear corner.

2. Before driving a vehicle with a dual air brake system, you must wait for the air compressor to build a minimum of ____ in both the primary and secondary systems.

25 psi

50 psi

75 psi

100 psi

Before driving a vehicle with a dual air brake system, you should wait for the air compressor to build up at least 100 psi in both the primary and secondary systems.

3. An air compressor governor will stop the compressor from pumping air once the air tanks have an air pressure level of:

125 psi.

100 psi.

150 psi.

80 psi.

An air compressor governor will stop the compressor from pumping air once the air tanks are at an air pressure level of 125 psi. This air pressure level is referred to as the "cut-out" level.

4. Brake fading is caused when:

Brakes are not used often enough.

Brakes overheat.

Brakes are too cold.

Brakes are wet.

Using the brakes excessively will cause them to overheat, making them less effective. This is referred to as "fading."

5. All air tanks must include:

A drain valve.

A lock.

A trap door.

A warning sticker.

Air brake system tanks must contain drain valves. These valves are used to drain accumulated oil and water from the tanks and may be either manually or automatically operated.