Skip to main content
DMV Test Free
ENES

Practice test 6 of 10

Mississippi CDL — Air Brakes Practice Test 6

The Mississippi 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 stop-and-go traffic you keep pressing and releasing the brake pedal far more than you need to. What could this lead to?
  2. 2.A parked truck slowly loses all its air overnight through a small leak. Why does its parking brake keep holding?
  3. 3.On a long downgrade in the right low gear, your 'safe' speed is 50 mph. You just braked down to about 45 mph and let off. When do you brake again?
  4. 4.During your walk-around, you spot a crack in a brake drum. When is the crack too long?
  5. 5.During controlled braking in an emergency, how should you handle the steering wheel while the brakes are applied?
  6. 6.During the walk-around, what are you checking for on the air hoses that feed the brake chambers?
  7. 7.Some pre-1975 trucks carry a front brake limiting valve worked from the cab. What was it meant to do, and what is the catch?
  8. 8.After heavy brake use, your tank pressure sinks to around 100 psi. In a properly working system, what should happen next?
  9. 9.An air-braked straight truck (not a tractor) was built in June 1997. Was it required to come with antilock brakes?
  10. 10.With s-cam brakes, what draws the shoes back off the drum once you let up on the pedal?

0 of 25 answered