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 Kansas 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. Applying the brake pedal causes air pressure to activate an electric switch and:

Turn off the brake lights.

Turn on the low pressure warning light.

Turn on the brake lights.

Turn off the low pressure warning light.

In a vehicle with air brakes, the brake lights are activated when the brake pedal is pushed and air pressure moves an electric switch. With the application of air pressure, the switch will then turn on the brake lights.

8. How should you test the low pressure warning signal?

Engage and disable the parking brake.

Rapidly press and release the brake pedal.

Open the rear shut-off valves.

Uncouple and recouple all glad hands.

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.

9. A modulating control valve can control the:

Spring brakes.

Landing gear.

Air brakes.

Anti-lock braking system (ABS).

A modulating control valve allows a driver to gradually apply spring brakes. In equipped vehicles, the valve is controlled by a lever located on the dashboard.

10. Both systems in a dual air brake systems share:

Air tanks.

Hoses.

Air lines.

An air compressor.

Both systems in a dual air brake system share a single air compressor. If the air compressor is damaged, neither system will be able to operate properly.

11. What do anti-lock brakes do?

Help a driver avoid wheel lockup

Lock up the front wheels

Prevent a vehicle from accelerating while traveling uphill

Prevent a vehicle from accelerating while traveling downhill

The function of an Anti-Lock Braking System (ABS) is to prevent the vehicle's wheels from locking up from hard brake application.

12. 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.

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