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Practice test 7 of 10

Illinois CDL — Air Brakes Practice Test 7

The Illinois 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.On a typical air-brake vehicle, a visible low-air warning must appear before pressure drops below what level?
  2. 2.Why is it discouraged to manually adjust an automatic slack adjuster to correct a long push-rod stroke?
  3. 3.You find you must keep increasing application pressure to hold a steady speed. What does this most likely indicate?
  4. 4.On some buses, what does a separate air tank tied to a dual parking control valve allow?
  5. 5.While you are driving normally, what keeps the strong springs of the spring brakes from applying the brakes?
  6. 6.As air is used up, at approximately what pressure does the governor let the compressor start pumping again?
  7. 7.What tends to gather at the bottom of the air tanks, making draining necessary?
  8. 8.What is the 'wig wag' device on some air brake vehicles?
  9. 9.On a tractor or straight truck, spring brakes come fully on in what pressure range, and what should you do beforehand?
  10. 10.Where would you look for the yellow ABS malfunction lamp on a trailer?

0 of 25 answered