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 North Carolina 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

19. The most common type of foundation brake used is the:

S-cam drum brake.

C-cam drum brake.

G-cam disc brake.

P-cam disc brake.

The most common type of foundation brake is an s-cam drum brake.

20. Truck tractors with air brakes built on or after March 1, 1997 must have:

An Anti-Lock Braking System (ABS).

Bluetooth.

GPS.

A rear back-up camera.

Truck tractors with air brakes built on or after March 1, 1997 must be equipped with Anti-Lock Braking Systems (ABS).

21. The parking brake should be:

Used whenever you park your vehicle.

Used while driving.

Set when driving in bad weather.

Removed.

The parking brake in a vehicle with air brakes should be used every time the vehicle is parked.

22. In a dual air brake system:

Each system has separate air tanks, hoses, and lines.

The systems share air tanks, but each has its own separate hoses and lines.

Each system uses the same lines and hoses.

One system is the main braking system and a second system is ready to be used if the first one fails.

A dual air brake system is made up of two separate air brake systems. The systems share a single set of brake controls, but each has its own air tanks, hoses, and lines.

23. Pressing and releasing a brake pedal unnecessarily can:

Release air faster than it can be replaced.

Add more air to the braking system.

Make the brake pedal more sensitive.

Create a loud noise.

In an air brake system, pressing and releasing the brake pedal unnecessarily can release air from the braking system faster than the compressor can replace it.

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

Ride the brakes all the way down the hill.

Apply the brakes for a few seconds, then release the brakes for a few seconds. Continue to repeat these steps as you travel down the hill.

Apply the brakes only near the bottom of the downgrade.

Apply consistent pressure to the brake pedal all the way down the hill.

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.

25. Foundation brakes are used:

Only at the front wheels.

Only at the rear wheels.

Only at the driver’s side wheels.

At each wheel.

Foundation brakes are used at each wheel. The most common type is the S-cam drum brake.

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