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Free New Jersey CDL Air Brakes Test 2025

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

Today, it is time to practice for New Jersey’s CDL air brake exam, with questions carefully based on the New Jersey Commercial Driver License Manual. Each of these multiple-choice questions is meant to simulate a real question that you will face on the real examination. However, our questions each include a hint and an explanation so that you can learn more about the subject matter and be able to answer questions in the future about the same topics that may be worded differently. Read the explanations carefully, practice as often as you need to until you feel comfortable, and good luck on your upcoming air brake exam!

Perfect for

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