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

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

2 / 40

What are slack adjusters?

3 / 40

What does the service brake system do?

4 / 40

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

5 / 40

Select the statement that tells you how you can check the low pressure warning signal.

6 / 40

Should the air pressure in the service air tanks fall below____the driver must be alerted via warning mechanism in the truck cab.

7 / 40

Select the true statement about tractor protection valve:

8 / 40

Spring brakes are usually held back by_____during normal driving.

9 / 40

Water is drained from the compressed air tanks because:

10 / 40

When does stab braking occur?

11 / 40

The parking brakes should be used____in air brake vehicles.

12 / 40

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

13 / 40

The best way to describe a dual air brake system is:

14 / 40

Select which vehicles are required to have a low air pressure warning signal:

15 / 40

Select the purpose of fanning air brakes:

16 / 40

You should be in the proper gear before going down a hill because:

17 / 40

Select the answer that is not a part of the braking process when driving a tractor-trailer combination vehicle that has ABS:

18 / 40

Where is compressed air stored?

19 / 40

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

20 / 40

The safety valve is usually set to open at:

21 / 40

After the initial drop, the maximum leakage rates per minute is:

22 / 40

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

23 / 40

Is it mandatory that all vehicles with air brakes have low air pressure warning signals?

24 / 40

Air pressure should build___with a dual air system.

25 / 40

You should_____when the low pressure warning is activated:

26 / 40

What does the drain valve for air tanks remove?

27 / 40

Select how you would check the truck's slack adjusters.

28 / 40

How do you test your service brakes?

29 / 40

You should brake on a long steep downgrade hill as a supplement to the braking effects of the engine

30 / 40

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

31 / 40

What must vehicles with air brakes have?

32 / 40

Air tanks should be drained:

33 / 40

What are spring brakes?

34 / 40

Select when you should use the parking brake:

35 / 40

Select the reason as to why air tanks need to be drained:

36 / 40

You should_____when checking the slack adjusters on S-Cam brakes.

37 / 40

The best way to test the low air pressure warning signal is to:

38 / 40

Select the statement that is not part of the air-brake system:

39 / 40

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

40 / 40

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

Your score is

The average score is 81%

5/5 - (1 vote)

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