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Practice test 4 of 10

Illinois CDL — Air Brakes Practice Test 4

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.After the start-up bulb check, the ABS malfunction lamp stays lit. What does that most likely mean?
  2. 2.The governor halts the compressor from adding more air once tank pressure climbs to about what value?
  3. 3.If a truck's air compressor is built with its own oil supply, what should you do before driving?
  4. 4.At 55 mph on dry pavement, roughly how much distance does air brake lag add?
  5. 5.While you are driving normally, what keeps the strong springs of the spring brakes from applying the brakes?
  6. 6.How do you test the low air pressure warning during the final air brake check?
  7. 7.Why can you still apply the brakes several times even if the compressor quits?
  8. 8.In a dual air system at operating rpm, air pressure should climb from 85 to 100 psi within about how long?
  9. 9.Which foundation brake design is found on most vehicles with air brakes?
  10. 10.Where would you look for the yellow ABS malfunction lamp on a trailer?

0 of 25 answered