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Air Brakes Practice Test 1

Last updated on May 5, 2023

Air Brakes Practice Test 1 contains Air Brakes knowledge and safe driving information that all commercial drivers should know to successfully pass the CDL “Air Brakes” written test.

CDL Air Brakes Practice Test 1 Methods:

Number of practice test questions with answers: 25

Number of correctly answered practice test questions needed to pass: 20

Passing score: 80%

Air Brakes Practice Test #2

This CDL Air Brakes Practice Test #1 with Answers is applicable for all 50 States.

CDL Air Brakes Practice Test (#1) With Answers



#1. A fully charged air system typically has ____ psi:

#2. Brake drums:

#3. To test the air leakage rate you should:

#4. When the low-pressure warning is activated, you should:

#5. When you apply pressure to the brake pedal, you are:

#6. When the safety valve releases air it means that:

#7. You still have normal brake functions if your ABS is not working.

#8. The air compressor is connected to the engine through:

#9. To check the slack adjusters on S-Cam brakes, you should:

#10. All vehicles with air brakes are required to have a low-pressure warning signal. This could be:

#11. The Governor allows the air to start pumping again when it reaches the cut in level, or around:

#12. The use of brakes on a long, steep downgrade is only a supplement to the braking effect of the engine.

#13. A dual air brake system:

#14. The Governor stops pumping air when it reaches the "cut out" level, at around:

#15. Some air brake systems have an alcohol evaporator which helps:

#16. Air brakes take longer to stop than hydraulic brakes because:

#17. An air pressure gauge:

#18. Which type of brake is the most common on commercial motor vehicles (CMVs)?

#19. To test your service brakes you should:

#20. You should use the parking brake:

#21. Stab braking occurs when you:

#22. Compressed air is stored:

#23. To test the low-pressure warning signal, you should do all of the following, EXCEPT:

#24. The proper way to go down long grades is to:

#25. The air tanks should be drained how often?


Air Brakes Practice Test #2


The pool of questions used to produce this practice test have been independently created by CDL Digest and come directly from Code of Federal Regulations (Title 49 – Transportation) and the information provided in AAMVA’s “2005 CDL Test System (July 2010 or newer Version) Model Commercial Driver Manual”.

These are the same sources that all 50 State Driver Licensing Agencies (SDLA) are required to use by federal regulation (49 C.F.R. 383.133) to develop the pool of questions for all written tests needed for a person to obtain a commercial learner’s permit (CLP), commercial driver’s license (CDL), and/or any federally authorized endorsements.

Note: The above listed source information is static, meaning changes to the information used to create the pool of questions that your State Driver Licensing Agency (SDLA) uses for the actual written test have been extremely rare over the decades. Due to the static nature of the source information, you may see practice test questions and answers that are very similar, if not identical to the questions and answers on the actual written test. If this occurs, it is purely coincidental. CDL Digest is not affiliated with the AAMVA or any government agency.


The source material used by CDL Digest to develop these practice test questions is very technical. Relying solely on the practice tests we have produced will not be enough to successfully pass the actual written tests. You will NEED to study in order to successfully pass these practice tests and the actual written tests.

Air Brakes Study Guide

Class “A” Commercial Learner’s Permit Study Guide

Class “B” Commercial Learner’s Permit Study Guide

Complete CDL Study Guide

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