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Practice test 6 of 10

Oklahoma CDL — Air Brakes Practice Test 6

The Oklahoma CDL — Air Brakes knowledge test has ~25 questions; you need ~20 correct (80%) to pass.

This practice test follows that format: 25 questions, pass with 20 correct. Answer every page, then grade it to see the answers and explanations.

Questions 1–10 of 25

  1. 1.While a vehicle is being driven, what holds the powerful springs of the spring brakes back?
  2. 2.In a dual air brake system, what happens to stopping ability if one of the two systems is very low on pressure?
  3. 3.What is the main cause of brake fade?
  4. 4.On tractors and straight trucks, spring brakes come fully on when air pressure falls into which range?
  5. 5.What color are the ABS malfunction lamps that warn of a fault?
  6. 6.How is the air compressor usually driven by the engine on an air brake vehicle?
  7. 7.When checking a slack adjuster on an s-cam brake, about how far can it move before it likely needs adjusting?
  8. 8.What does 'brake lag' refer to in an air brake system?
  9. 9.In a dual air system with the engine at operating rpm, air pressure should build within which range and time?
  10. 10.Why is it important to drain the air storage tanks completely?

0 of 25 answered