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 answer choices. To pass, the applicant must answer at least 20 questions correctly. Test questions come from the Louisiana 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. Manual air tank drains should be:

Opened to drain the tanks after each day.

Left open while driving.

Sealed with glue.

Compressed air in an air brake system usually contains a certain amount of water and compressor oil. The water and oil can damage the brakes if left to accumulate in the system. Manually operated air tank drains must be opened daily to remove this build-up.

2. When stopping in an emergency situation, you should:

Veer your trailer to the right and stop.

Stop in a straight line.

Veer your trailer to the left and stop.

If you need to make an emergency stop, you can use either the controlled braking method or the stab braking method. It's important to brake in a way that keeps your vehicle in a straight line but will still allow you to turn if necessary.

3. Brakes out of adjustment will:

Work properly.

Cause some of the brakes to overwork and malfunction.

Allow better acceleration.

Brakes out of adjustment will fade before those that are properly adjusted. Brake adjustment must be checked frequently to help prevent brake issues.

4. Do not operate a vehicle if any brake drums have cracks that are larger than ____ of the width of the friction area.

One half

One third

One fifth

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. An air compressor governor controls:

When the air compressor pumps air into the air storage tanks.

How fast air is pumped into the air storage tanks.

The temperature of the air pumped into the air storage tanks.

In an air brake system, the air compressor governor controls when the air compressor pumps air into the air storage tanks.

6. If the low air pressure warning signal comes on, you should:

Continue driving, but have the brakes repaired within a week.

Pull over and inspect the brakes.

Phone a mechanic while driving.

If the low air pressure warning signal comes on while you are driving a vehicle with air brakes, you should immediately bring the vehicle to a safe stop while you are still able to control the brakes. Inspect and repair the brakes as soon as possible.

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