CDL Air Brake - Commercial Driver's License Air Brakes Air Brake System Components Questions and Answers

Question 1

What is the primary function of the air compressor governor in an air brake system?

Accepted Answer

To control when the air compressor pumps air into the storage tanks.

Answer

To cool the compressed air before it enters the air tanks.

Answer

To filter oil and water out of the compressed air.

Answer

To regulate the pressure applied to the brakes when the pedal is pressed.

Question 2

A driver is operating a vehicle in freezing temperatures. Which component is specifically designed to help prevent ice from forming in the air brake valves?

Accepted Answer

Alcohol evaporator

Answer

Air dryer

Answer

Safety valve

Answer

Slack adjuster

Question 3

While monitoring the gauges, a driver notices the application pressure gauge. What information does this specific gauge provide?

Accepted Answer

The amount of air pressure currently being used to apply the brakes.

Answer

The total amount of air pressure available in the primary and secondary tanks.

Answer

The air pressure required for the spring brakes to engage.

Answer

The manufacturer's recommended maximum air pressure for the system.

Question 4

Which of the following components has a safety feature that is typically set to open and release excess air pressure at approximately 150 psi?

Accepted Answer

The safety relief valve

Answer

The air compressor governor

Answer

The brake pedal (treadle valve)

Answer

The slack adjuster

Question 5

A driver presses the brake pedal (foot valve or treadle valve). What is the direct action of this component within the air brake system?

Accepted Answer

It opens a valve that releases compressed air from the storage tanks towards the brake chambers.

Answer

It mechanically forces the brake shoes against the drum.

Answer

It sends a signal to the air compressor to start pumping air.

Answer

It drains moisture and oil from the air tanks.

Question 6

What is the main purpose of draining air tanks regularly, especially if the vehicle is not equipped with automatic drain valves?

Accepted Answer

To remove accumulated water and compressor oil, which can cause brake failure.

Answer

To increase the maximum air pressure the system can hold.

Answer

To reduce the overall weight of the vehicle.

Answer

To cool down the air compressor after a long trip.