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Practice test 9 of 10

Missouri CDL — Air Brakes Practice Test 9

The Missouri 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.At roughly what tank pressure does the governor tell the compressor to stop pumping (cut-out)?
  2. 2.Why do air brakes have 'brake lag' that hydraulic brakes do not?
  3. 3.What does it likely mean if the yellow ABS malfunction lamp stays lit after the start-up bulb check?
  4. 4.The governor lets the compressor start pumping again once tank pressure falls to about what level (cut-in)?
  5. 5.What is a 'wig wag' device?
  6. 6.What is the benefit of a modulating control valve for the spring brakes?
  7. 7.In the recommended downgrade braking pattern, once your speed is about 5 mph below your safe speed, what do you do?
  8. 8.Why should you avoid pressing the foot brake while the spring brakes are already applied?
  9. 9.The low air pressure warning must come on before tank pressure falls below what level?
  10. 10.Current guidance says front-wheel braking is:

0 of 25 answered