Free CDL Air Brakes Endorsement Practice Test Questions

CDL Test Study Guide with Practice Questions
1. Why must air tanks be drained?
  1. To drain all the air out of the tank. 
  2. To drain moisture and oil out of the tank. 
  3. To keep anyone from moving the vehicle.
2. What is a supply pressure gauge used for?
  1. To tell you how much diesel is in the vehicle. 
  2. To tell you how much water is in the air tank. 
  3. To tell you how much air is in the air tank.
3. All vehicles with air brakes must have a low air pressure warning signal.
  1. True 
  2. False
4. What are spring brakes?
  1. Brakes used for parking. 
  2. If the air brakes leak down, springs press the brakes on to stop the vehicle. 
  3. The spring on the brake pedal.
5. Front wheel brakes are good under all conditions.
  1. True 
  2. False
6. When you put your brakes on the air brake system works with an electric switch to turn on the brake lights.
  1. True 
  2. False
7. What do air brakes use to make the brakes work?
  1. Compressed gas 
  2. Compressed oil 
  3. Compressed air
8. Air brakes are really three different braking systems: service brake, parking brake and emergency brake.
  1. True 
  2. False
9. The service brake applies and releases:
  1. The parking brake when you use the parking brake control. 
  2. The brake when you use the brake pedal during normal driving. 
  3. In the event of an emergency.
10. The parking brake applies and releases:
  1. The brake pedal during normal driving. 
  2. In the event of an emergency. 
  3. The parking brakes when you use the parking brake control.
11. The emergency brake system:
  1. Uses parts of the service and parking brake system to stop the vehicle in the event of a brake system failure. 
  2. Uses the service brake to stop the vehicle in the event of a brake system failure. 
  3. Uses the parking brake to stop the vehicle in the event of a brake system failure.
12. The governor controls when the air compressor will pump into the air storage tanks.
  1. True 
  2. False
13. The air storage tanks are used to hold compressed air.
  1. True 
  2. False
14. When you put on the brakes by pushing down the brake pedal:
  1. The air pressure is reduced to the brake pads. 
  2. Air pressure is applied to the brake pads. 
  3. Compressed air is let go out of the system.
15. The S-cam forces the brake shoes away from one another and presses them against the inside of the brake drum. It is called the S-cam because:
  1. It is shaped like the letter Z. 
  2. It is shaped like the letter N. 
  3. It is shaped like the letter S.

 

Answer Key

1. B 
2. C 
3. A 
4. B 
5. A 
6. A 
7. C 
8. A 
9. B 
10. C 
11. A 
12. A 
13. A 
14. B 
15. C