CDL Air Brakes Test


This is the Commercial Vehicle Driver's License Test covering Air Brakes.  You will be presented with 40 questions and you must answer 34 questions correctly to pass.  There is no time limit.  You may not go back once you answer a question.  Click the "Start Quiz" button below to begin.  Good luck!

1 / 40

Select the true statement about what the Air Compressor Governor controls:

2 / 40

What keeps air in the tanks should the air compressor develop a leak?

3 / 40

A leak rate for a straight truck or bus air brake system should not exceed _____psi per minute when the engine is off and the brakes are released.

4 / 40

You should_____to make an emergency stop with air brakes when using the stab braking method.

5 / 40

At around____the governor allows the air compressor to start pumping again:

6 / 40

Why are you required to take an exam about air brakes?

7 / 40

An example of a low pressure warning signal for air brakes is:

8 / 40

What are spring brakes?

9 / 40

Spring brakes are usually held back by_____during normal driving.

10 / 40

Air brake systems should not lose air faster than____when testing for air leakage rates in combination vehicles before applying the brake pedal.

11 / 40

The best way to test if the spring brakes come on automatically is to:

12 / 40

How can you check slack adjusters?

13 / 40

What is a supply pressure gauge used for?

14 / 40

How often should you drain your air tanks?

15 / 40

The method used to make sure the spring brakes will come on automatically is to:

16 / 40

What does it man when the safety valve releases air?

17 / 40

When should you avoid using the parking brake?

18 / 40

You should____to check the free play of manual slack adjusters on S-Cam brakes.

19 / 40

With the engine cutt off and the brakes released the air loss in a straight truck or bus should not be more than:

20 / 40

When should you drain air tanks that do not have an automatic tank drain?

21 / 40

Air tanks should be drained:

22 / 40

Select whether the following statement is true or false: Front wheel brakes are good to use in all conditions.

23 / 40

A slack adjuster is:

24 / 40

Select the true statement in regards to an application pressure gauge:

25 / 40

Select the true statement in regards to your brake function when your ABS fails

26 / 40

When does your vehicle's single brake system need an adjustment?

27 / 40

Select the inappropriate way to test for the low pressure warning signal.

28 / 40

When does stab braking occur?

29 / 40

Select the true statement about dual air brake systems.

30 / 40

Select how you can tell if your vehicle is equipped with an anti-lock braking system:

31 / 40

Front wheel brakes are good under what kind of conditions?

32 / 40

Should your air compressor stop working:

33 / 40

Air pressure should build___with a dual air system.

34 / 40

Select the factors that can cause your brakes to fade or fail:

35 / 40

Select the true statement about emergency brakes:

36 / 40

What are spring brakes?

37 / 40

How do you check the air compressor governor "cut in" and "cut out" pressures?

38 / 40

When should air tanks be drained?

39 / 40

Select the true statement in regards to brake drums:

40 / 40

You should___when driving down a long steep hill.

Your score is

The average score is 92%

5/5 - (1 vote)

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