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Free Mississippi CDL Air Brakes Test 2025

Part of mandatory Entry-Level Driver Training Course Based on 2025 MS commercial driver's license manualAvailable in EN, ES
30questions
6mistakes allowed
80%passing score

An important part of having the commercial driving career that you want is being able to drive any vehicle available, so that you have an edge over other drivers who might not be capable. This means that you must learn how to handle air brakes. Today, you will be taking a practice exam that will prepare you to pass the CDL air brakes exam, with 30 multiple-choice questions based directly on the Mississippi Professional Driver’s Manual. Each question comes with a hint, should you need it, and an explanation, which you should read carefully so that you are prepared to answer future questions about each topic. Take the exam as many times as you can, so that you are fully comfortable, and you’ll be completely ready for the real CDL air brakes exam, and a much safer driver in general!

Perfect for

  • First-time MS CDL and CLP applicants
  • CDL holders adding endorsements
  • MS CDL renewal applicants
MS commercial driver's license

What to expect on the actual exam

How many questions25
How many correct answers to pass20
Passing score80%
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List of questions (classic view)

  1. Which of the following is NOT part of the air brake system?
  2. When should you drain your air tanks?
  3. Which of the following are true about a dual air brake system?
  4. Slack adjusters are
  5. What is the best way to test your vehicle's low air pressure warning signal?
  6. Which of the following is NOT part of the braking process when driving a tractor-trailer combination vehicle with an anti-lock braking system (ABS)?
  7. Spring brakes are
  8. Which of the following will be true about your brake function if your anti-lock braking system (ABS) fails?
  9. How do brakes work on a long, steep downgrade?
  10. At what measurement is the safety valve USUALLY set to open?
  11. The tractor protection valve
  12. An anti-lock braking system (ABS)
  13. Which of the following is NOT part of the drum brake?
  14. After the initial drop, the maximum acceptable leakage rates per minute are
  15. Under which conditions are front wheel brakes good?
  16. Which vehicles must have low air pressure warning signals?
  17. Which of the following can cause brakes to fade or fail?
  18. How would you check your truck's slack adjusters?
  19. The purpose of a supply pressure gauge is
  20. Which of the following should you do before leaving your vehicle unattended?
  21. What is the best way to test if your vehicle's spring brakes come on automatically?
  22. If the air tanks are not drained,
  23. Why must you pass a knowledge test on air brakes?
  24. How can you tell if your vehicle is equipped with an anti-lock braking system (ABS)?
  25. When should you use the parking brake?
  26. The low air pressure warning signal will come on before the pressure in the air tanks falls below
  27. A low pressure warning signal is required on
  28. All vehicles equipped with air brakes have
  29. With air brake-equipped vehicles, the parking brakes should be used
  30. The use of air brakes on a downgrade is only a supplement to the

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