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Practice test 4 of 10

Wisconsin CDL — Air Brakes Practice Test 4

The Wisconsin 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.Using the proper braking technique on a downgrade, when do you release the brakes?
  2. 2.How do you use the controlled braking method in an emergency?
  3. 3.On a tractor or straight truck, the spring brakes come fully on when air pressure falls into what range?
  4. 4.What is the main function of an antilock braking system (ABS)?
  5. 5.What color is the ABS malfunction lamp on a tractor, truck, or bus?
  6. 6.The safety relief valve on the first air tank is usually set to open at what pressure?
  7. 7.What does a supply pressure gauge tell the driver?
  8. 8.When should you avoid setting the parking brakes and use wheel chocks instead?
  9. 9.In a dual air system at operating rpm, pressure should climb from 85 to 100 psi within about how long?
  10. 10.What is the main job of the air compressor in an air brake system?

0 of 25 answered