CDL Air Brakes Test 2 – Classic Mode

This is CDL Air Brakes Test 2 in our original Classic Mode. Simply click in your answer to each CDL practice test question. When you're finished, check your score and results. You can reset the test and retake it as needed.


Start Test #2 Now

1. The Air Compressor Governor controls...

A When the brakes should be applied
B When the air compressor pumps air into the storage tanks
C When the warning light is activated
D When the air is released from the tank

2. A dual air brake system...

A Has two air brake systems and one set of controls
B Takes less time to build air pressure
C Has one set of air tanks and hoses
D Must have two warning alarms

3. An emergency brake...

A Is required on commercial vehicles
B Must be held on by mechanical force
C Could be activated by the loss of air pressure
D All of the above

4. To check the slack adjusters on S Cam brakes, you should...

A Leave the parking brakes on and pull on the slack adjuster
B Wear gloves and pull hard on each slack adjuster
C Make sure the slack adjusters move more than one inch each way
D Drain the air from the system and pull on the slack adjusters

5. To test the low pressure warning signal, you should do all BUT the following...

A Shut the engine off
B Turn the electrical power on
C Ask a friend to listen for the signal
D Step on and off the brake pedal to reduce air pressure

6. With dual air systems, the air pressure should build...

A From 85 to 100 psi in 45 seconds
B From 70 to 100 psi in 60 seconds
C From 85 to 150 psi in 45 seconds
D From 70 to 150 psi in 60 seconds

7. A fully charged air system typically has ____ psi.

A 100
B 125
C 150
D 175

8. To test the air leakage rate you should...

A Leave the engine running and release the service brake
B Turn off the engine and release the service brake
C Charge the air system and leave the engine running
D Depress the brake pedal and monitor the air pressure gauge

9. When testing air leakage rates for combination vehicles (before applying the brake pedal), air brake systems should not lose air faster than...

A 2 psi per minute
B 3 psi per 30 seconds
C 3 psi per minute
D 4 psi per minute

10. To check the air compressor governor "cut in" and "cut out" pressures...

A Run the engine at a fast idle
B Step on and off the brake to reduce tank pressure
C Monitor the air pressure gauge
D All of the above

End of Test #2

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