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 New Jersey Commercial Driver Guide. 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

1. Before driving a vehicle with air brakes, you should ensure that the spring brakes come on automatically when:

Air pressure falls below 45 psi.

Air pressure falls below 20 psi.

Driving downhill.

Driving uphill.

Before driving a vehicle with air brakes, you should ensure that the spring brakes come on automatically when air tank pressure falls to a level between 20 and 45 psi. You can do this by chocking the wheels and releasing air from the braking system by stepping on and off the brake pedal. Once the pressure drops to an unsafe level, the parking brake valve should pop out and spring brakes should come on.

2. 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.

3. 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.

4. Test the low pressure warning signal:

Once a month.

Once a week.

Twice a week.

Before every trip.

It is essential that your low pressure warning light function 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.

5. When inspecting your brakes, a slack adjuster should move ____ from where it is attached to the push rod.

At least three inches

More than two inches

Up to five inches

No more than one inch

Check each slack adjuster after setting wheel chocks and disengaging the parking brake. Pull the slack adjusters to make sure they do not move more than about one inch from where the push rod is attached. If they move more than one inch, they may be out of adjustment and will need to be fixed.