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Practice test 7 of 10

Wisconsin CDL — Air Brakes Practice Test 7

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.In stab braking, why must you wait for the wheels to start rolling before reapplying the brakes?
  2. 2.At about what tank pressure does the governor let the compressor begin pumping again?
  3. 3.In a dual air system at operating rpm, pressure should climb from 85 to 100 psi within about how long?
  4. 4.On a tractor or straight truck, the spring brakes come fully on when air pressure falls into what range?
  5. 5.Before driving a vehicle with dual air brakes, you should wait until pressure reaches at least what level in both systems?
  6. 6.What does the tractor protection valve do if the air supply drops while you are driving?
  7. 7.What is 'brake lag' in an air brake system?
  8. 8.If you keep driving after the low air warning comes on, what limits your braking?
  9. 9.On a bus with a separate air tank for releasing the spring brakes, why must you plan your moves carefully?
  10. 10.What must you always do before leaving your vehicle unattended?

0 of 25 answered