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 two, three or four answer choices. To pass, the applicant must answer at least 20 questions correctly. Test questions come from the Nebraska 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

1. A low air pressure warning signal:

Is not recommended on vehicles with air brakes.

Is required on vehicles with air brakes.

Is optional on vehicles with air brakes.

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

2. Air brakes use ____ to function.

Compressed air

Liquid nitrogen

Carbon dioxide

The brakes in an air brake system use compressed air to function properly.

3. During a static leakage test, what is the maximum leakage rate that is safe for a double combination vehicle?

3 psi in one minute.

6 psi in one minute.

8 psi in one minute.

When performing a static leakage test on a double combination vehicle with air brakes, the leakage rate should be no more than 3 psi in one minute. If the air leaks from the air brake system at a quicker rate, the vehicle should not be driven because something likely needs to be repaired.

4. While driving downhill, you should brake until you reach a speed that is ____ below your safe speed, then release the brake pedal.

5 mph

10 mph

15 mph

20 mph

While driving downhill, you should hold down the brake pedal until your vehicle reaches a speed 5 mph below your safe speed, then release the brake pedal. Repeat this process.

5. You should ____ if the low pressure warning signal activates while you are driving.

Stop where you are and park

Exit the roadway as soon as safely possible

Continue driving normally

If the low pressure warning signal activates while you are driving, it is important that you safely exit the roadway as soon as possible and park your vehicle. If the air pressure gets too low, the brakes will no longer work well enough for you to stop safely.

6. When using the controlled braking method in an emergency situation, you should:

Apply the brakes as hard as possible without locking the wheels.

Apply the brakes with about half of your usual force.

Apply the brakes so the wheels lock.

Apply the brakes with minimal pressure.

The controlled braking method for emergency stops involves applying the brakes as hard as you can without locking the wheels. Keep steering wheel movements small when braking in this way.

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