Your Progress

  • 0 Correct
  • 0 Incorrect
  • 0 Skipped
10 mistakes allowed to pass
100% of users found this test helpful.
Click a star to add your vote
5 votes • average 5 out of 5
  • Back to all tests
  • Score Page
  • 0 Correct
  • 0 Incorrect
  • 0 Skipped

ON Air Brake Test 3 2024

5 out of 5 • 5 votes.
Based on 2024 ON commercial driver's license manual Instant feedback

Driving a commercial vehicle is very different from driving a car. Trucks have different controls and different blind spots. As a commercial vehicle operator, you must travel long distances and face a variety of traffic and weather conditions. You must also be prepared to deal with emergencies such as fires and collisions. Before you can get your commercial driver’s licence in Ontario, you must study and practice to learn to drive carefully and safely. To get your commercial driver’s licence, you must pass both a written and a practical test. The written test (also known as the truck driver’s licence knowledge exam) has several multiple-choice questions. If you are looking for a practice test before taking the commercial driver’s licence knowledge test, this is the place. This practice test will help you prepare. Please note that this is a sample test and does not replace the official truck driver’s knowledge exam. There are 49 questions with hints and explanations of the correct answer. All questions are based on the official 2024 ON commercial driver’s manual. If you have any questions or comments, please contact us. Good luck!

Ensuring the accuracy and quality of our practice tests is paramount. Learn more about our rigorous standards in our Commitment to Accuracy article.

Perfect for:

  • First-time ON commercial license applicants
  • Existing commercial license holders adding endorsements
  • ON commercial license renewal applicants

What to expect on the actual ON commercial license exam:

  • 25 questions
  • 20 correct answers to pass
  • 80% passing score

More FREE ON Commercial Driving Resources:

  1. General Knowledge 1
  2. General Knowledge 2
  3. General Knowledge 3
  4. General Knowledge 4
  5. General Knowledge 5
  6. General Knowledge 6
  7. General Knowledge 7
  8. Road Signs
  9. Road Signs 2
  10. General Knowledge Marathon
  11. General Knowledge Exam Simulator
  12. Class A Licence Test 1
  13. Class A Licence Test 2
  14. Class A Licence Test 3
  15. Class A Licence Marathon
  16. Class A Licence Exam Simulator
  17. Class B Licence Test 1
  18. Class B Licence Test 2
  19. Class B Licence Test 3
  20. Class B Licence Test 4
  21. Class B Licence Test 5
  22. Class B Licence Test 6
  23. Class B Licence Test 7
  24. Class B Licence Test 8
  25. Class B Licence Test 9
  26. Class B Licence Test 10
  27. Class B Licence Test 11
  28. Class B Licence Marathon
  29. Class B Licence Exam Simulator
  30. Class C Licence Test 1
  31. Class C Licence Test 2
  32. Class C Licence Test 3
  33. Class C Licence Test 4
  34. Class C Licence Test 5
  35. Class C Licence Test 6
  36. Class C Licence Test 7
  37. Class C Licence Test 8
  38. Class C Licence Test 9
  39. Class C Licence Test 10
  40. Class C Licence Test 11
  41. Class C Licence Marathon
  42. Class C Licence Exam Simulator
  43. Class D Licence Test 1
  44. Class D Licence Test 2
  45. Class D Licence Test 3
  46. Class D Licence Marathon
  47. Class D Licence Exam Simulator
  48. Class F Licence Test 1
  49. Class F Licence Test 2
  50. Class F Licence Test 3
  51. Class F Licence Test 4
  52. Class F Licence Test 5
  53. Class F Licence Test 6
  54. Class F Licence Test 7
  55. Class F Licence Marathon
  56. Class F Licence Exam Simulator
  57. Air Brake Test 1
  58. Air Brake Test 2
  59. Air Brake Test 3 (you are here)
  60. Air Brake Test 4
  61. Air Brake Test 5
  62. Air Brake Test 6
  63. Air Brake Test 7
  64. Air Brake Test 8
  65. Air Brake Test 9
  66. Air Brake Test 10
  67. Air Brake Test 11
  68. Air Brake Test 12
  69. Air Brake Test 13
  70. Air Brake Test 14
  71. Air Brake Marathon
  72. Air Brake Exam Simulator
  73. AZ Licence Exam Simulator

List of questions (classic view)

  1. The air compressor should be inspected only when
  2. For the air brake inspection, what do you check first?
  3. In an S-cam drum brake, which of the following is connected to the brake spider?
  4. A brake shoe is not a part of
  5. Brake chambers are found on
  6. It does not matter if a small amount of oil is discovered during drainage of
  7. Compressed air from the air compressor first goes to the
  8. Compressed air exhaust is
  9. Compressed air entering the brake chambers applies
  10. Evacuating air from the brake chambers will apply
  11. A brake lining that has become contaminated with oil or grease indicates a problem with the
  12. An air line shows signs of wear from rubbing, but there are no leaks because the inner tube is still in good shape. What should you do?
  13. An alcohol evaporator or air dryer can
  14. Which tank is likely to collect the most moisture?
  15. Your vehicle will fail the air tank drain valve test if
  16. There is a split-second delay in activation of _________. There is no delay in activation of _________.
  17. The braking system converts the kinetic energy of the moving vehicle into
  18. When you drain the air tanks, which tank should you drain first?
  19. What is the purpose of the governor?
  20. The air compressor is powered by the
  21. Air pressure monitoring gauges are located on the _________ of the vehicle.
  22. The pushrod stroke occurs when compressed air enters
  23. When you press the brake pedal, the valve underneath the brake pedal ________ to apply the service brakes.
  24. Which of the following is part of a disc brake?
  25. If the low air pressure warning signal comes on, what should you do?
  26. In a tractor-trailer, an anti-compounding valve is connected to
  27. In Canada, automatic slack adjusters have been installed on trucks and trailers manufactured since
  28. When you use the free stroke (pry bar) method, the pushrod should not move more than
  29. If your vehicle is equipped with automatic slack adjusters, why must you fully apply the service brakes regularly?
  30. In Canada, antilock braking systems (ABS) have been mandatory on all trucks and buses over 4,560 kg that have been manufactured since
  31. Which of these significantly decreases the braking force produced at the wheel?
  32. Which type of trailer can be towed before the service tanks are full?
  33. In determining how well your air brake system works, which is NOT a significant factor?
  34. In large commercial vehicles, most air brake systems use automatic valves to
  35. Where are a vehicle's air tanks located?
  36. What is the "cut-in" level?
  37. Normally, who can adjust automatic slack adjusters?
  38. Which statement is true of spring brakes?
  39. Which colour coding is usually employed for the service line?
  40. Why are there two service tanks in a modern air brake system?
  41. What is a "glad hand"?
  42. What function does the alcohol evaporator perform?
  43. To inspect an air brake system, you should wear
  44. When must you chock the wheels of your stopped vehicle?
  45. Finding a small bit of oil during an inspection is NOT serious if it's coming from
  46. When inspecting the brake chambers, you should check for which of the following?
  47. Cut-in pressure must never be lower than
  48. What colour is the parking brake control button?
  49. In an air brake system, spring brakes are intended for
  50. The pushrod stroke occurs when compressed air enters the