All tests
 
 
 
 
 

Did you know

Save questionQuestion savedSaveSaved
Close

Free District of Columbia CDL Air Brakes Test 2024

Part of mandatory Entry-Level Driver Training Course Based on 2024 DC commercial driver's license manualAvailable in EN, ES
30questions
6mistakes allowed
80%passing score

The knowledge you have gained from studying air brakes will be tested so that you can become a safer driver today.
We have included 30 multiple-choice questions, carefully based on the District of Columbia Commercial Driver License Manual and the actual types of questions you will find on the DMV exam. A hint and an explanation have been provided for each question. Please read each explanation to gain further insight as you prepare for the questions on the actual DMV exam. Good luck on your exam, and drive safely!

Perfect for

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

What to expect on the actual exam

How many questions25
How many correct answers to pass20
Passing score80%
Unlock all 1,500+ exam-like questions for District of Columbia. Pass Guarantee

Become a member to unlock our extensive library of 1,500+ exam-like questions and get your District of Columbia ELDT certification online. Official FMCSA-approved national Entry-Level Driver Training provider.

Pass the first time, guaranteed Driving-Tests program displayed on a laptop

List of questions (classic view)

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

More resources

You may also like

DC CDL Handbook

View the most recent (2024) official DC CDL Handbook.

Open PDF
DC CDL Practice Test App

Download our free iOS or Android app and practice for your driving test offline or on the go.

CDL Genie app
10 Things You Should Do Before Your Driving Knowledge Exam (PDF)

Many people do their best but still get to the DMV overconfident and underprepared because they fail to do some of the simple...

Open PDF
10 Things You Should Do Before Your Driving Knowledge Exam (PDF)
Are you in another state?