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 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 25

Passing Score 20

13. The ____ between an air compressor and reservoir tank prevents air from escaping if the air compressor has a leak.

Slack adjuster

One-way check valve

Tractor protection valve

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.

14. In cold weather, an alcohol evaporator should be checked and filled:

Once a week.

Every day.

Every hour.

Once a month.

An alcohol evaporator can help prevent ice from building up in an air brake system. In cold weather, the evaporator should be checked and refilled every day.

15. In a vehicle with dual parking control valves, a separate air tank can be used:

To make the air brakes work more effectively.

To temporarily release the spring brakes.

To charge the brakes on the rear trailer.

In a vehicle with dual parking control valves, there is a separate air tank that can be used to temporarily release the spring brakes if they have been activated due to low air pressure. Pushing in the proper control will release the spring brakes for a short period of time, allowing the driver to move the vehicle in an emergency.

16. A wig wag is:

A low pressure warning device.

A tube that carries air to the brakes.

A type of air brake system.

Vehicles with air brakes are required to be equipped with a low pressure warning device. A wig wag is a type of low air pressure warning device. This device drops a mechanical arm into the driver's view if the pressure in the tanks drops to a level between 55 and 75 psi.

17. If one air system in a dual air brake system is very low on pressure:

None of the brakes will work at all.

Either the front or rear brakes will not be operating fully.

There will be no noticeable affect.

Lights on the outside of the tractor will flash.

In a dual air brake system, if one of the air systems gets very low on pressure, either the front or rear brakes will not be operating fully. You should bring your vehicle to a safe stop and have the air system repaired.

18. 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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