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Practice test 3 of 10

South Carolina CDL — Air Brakes Practice Test 3

The South Carolina 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.In the 'controlled braking' method for an emergency stop, how hard do you apply the brakes?
  2. 2.On a tractor or straight truck, at about what pressure range will the spring brakes come fully on by themselves?
  3. 3.What should you always do before leaving your vehicle unattended?
  4. 4.Where would you look for the ABS malfunction lamp on a trailer?
  5. 5.Using proper downgrade braking with a 'safe' speed of 40 mph, how should you use the brakes?
  6. 6.At roughly what tank pressure does the governor tell the compressor to stop pumping (the cut-out level)?
  7. 7.Why is it a bad idea to press and release the brake pedal repeatedly for no reason?
  8. 8.Why can a heavily loaded vehicle take a long distance to stop once the spring brakes come on?
  9. 9.In a dual air system, when should the low air pressure warning come on?
  10. 10.What is 'brake lag' in an air brake system?

0 of 25 answered