CDL Air Break Prep

Question 1

1. During normal operations, the parking and emergency brakes are usually held back by

Answer 1

Air pressure

Question 2

2. Three different systems are found on modern air brake systems; service brakes, parking brakes, and the

Answer 2

Emergency brakes

Question 3

3. Air brake equipped vehicles must have

Answer 3

An air pressure gauge, to show the pressure available for braking

Question 4

4. A straight truck or bus air brake system cannot leak more than ______ psi per minute with the engine off and the brakes released.

Answer 4

2

Question 5

5. If your vehicle is equipped with an alcohol evaporator, every day during the winter weather you should

Answer 5

Check and fill the alcohol level

Question 6

6. Which of the following statements about brakes is true?

Answer 6

The heavier a vehicle or the faster it is moving, the more heat the brakes have to absorb to stop it

Question 7

7. When a failure occurs in the service brake system, the system you need to stop the vehicle is the

Answer 7

Emergency brake system

Question 8

8. Which of the following is O.K. to find in the air brake system?

Answer 8

Air

Question 9

9. The most common type of foundation brake found on heavy commercial vehicles is

Answer 9

S-cam drum

Question 10

10. You must make a quick emergency stop. You should brake so you

Answer 10

Can stay in a straight line and maintain steering control

Question 11

11. Which brake system applies and releases the brakes when the driver uses the brake pedal?

Answer 11

The service brake system

Question 12

12. What will determine how effective the spring emergency brakes or the parking brakes work?

Answer 12

The adjustment of the service brakes

Question 13

13. To use the stab braking technique during emergency braking, you

Answer 13

Brake hard with the pedal until the wheels lock, then get off the brakes until the wheels begin to roll again

Question 14

14. The air compressor governor controls

Answer 14

When the compressor will pump air into the storage tanks

Question 15

15. If your vehicle has an alcohol evaporator, it is there to

Answer 15

Reduce the risk of ice in the air brake valves in cold weather

Question 16

16. Why should you not fan the brakes on and off during long downgrades?

Answer 16

The short time off the brakes does not allow for brake cooling

Question 17

17. Air loss in a single vehicle (not a combination unit) should not be more than ______ with the engine off and the brakes on.

Answer 17

2 psi in one minute

Question 18

18. How do you check the free play in manual slack adjusters?

Answer 18

Park on level ground, chock wheels, release the parking brakes and pull slack adjusters

Question 19

19. A combination vehicle air brake system cannot leak more than ______ psi per minute with the engine off and the brakes released.

Answer 19

3

Question 20

20. The brake pedal

Answer 20

Controls the air pressure applied to operate the brakes

Question 21

21. The air loss rate for a straight truck or bus with the engine off and the brakes applied should not be more than

Answer 21

2 psi in one minute

Question 22

22. If your truck or bus has dual parking control valves, you can use pressure from a separate tank to

Answer 22

Release the emergency brakes to move a short distance

Question 23

23. The air supply pressure gauge shows the driver how much pressure

Answer 23

Is available in the air tanks

Question 24

24. Which of the following answers is most correct about using brakes on a long and/or steep downgrade?

Answer 24

Use the braking effects of the engine and when the vehicle speed reaches the “safe” speed, apply brakes firmly until vehicle speed is reduced to approximately 5 mph below “safe” speed

Question 25

25. The vehicle must have a warning device which comes on when the air pressure in the service air tanks falls below

Answer 25

60 psi

Question 26

26. In air brake equipped vehicles, you use the parking brakes when?

Answer 26

Whenever you park the vehicle

Question 27

27. What turns on the electrical stop light switch in an air brake system?

Answer 27

Air pressure

Question 28

28. When using the parking brakes or emergency brakes, what type of pressure is being used?

Answer 28

Spring pressure

Question 29

29. If the air system should develop a leak, what will keep the air in the air tanks?

Answer 29

The one-way check valve

Question 30

30. The purpose of engine retarders is to

Answer 30

Help slow the vehicle while driving and reduce brake wear