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 Nevada 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
Passing Score

1. Air pressure should build up in a single air system within:

Explanation
In single air systems, air pressure should build from approximately 50 to 90 psi within three minutes.

2. A one-way check valve:

Explanation
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.

3. A low air pressure warning signal:

Explanation
Any vehicle with air brakes must be equipped with a low air pressure warning signal.

4. During a walk-around inspection, ensure there are no cracks on the brake drums that are more than ____ of the width of the friction area.

Explanation
Before beginning a trip, it is important to check the brake drums during your walk-around inspection. It is unsafe to drive if any brake drum has a crack more than one half of the width of the friction area.

5. The two markings on a front brake limiting valve usually read:

Explanation
Some vehicles with air brake systems manufactured before 1975 have a front brake limiting valve with "normal" and "slippery" settings.

6. Brake linings should be:

Explanation
Brake linings should not be loose or soaked with oil or grease. They shouldn't be dangerously thin.
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