Crist CDL free online BVM practice tests
AL Combination Fact Sheet
Questions on Test:
20
Correct answers needed to pass:
16
Passing Score:
80%
Age to apply:
18
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In normal driving, some drivers use the hand valve before applying the brake pedal to prevent a jackknife. Which of these statements is true?

Possible Answers:

It should not be done
It results in less skidding than using the brake pedal alone
It is the best way to brake and keep the truck in a straight line
Answer:
It should not be done
Explanation:
The trailer hand valve, also called the trolley valve or Johnson bar, works the trailer brakes. The trailer hand valve should be used only to test the trailer brakes. Do not use it in driving because of the danger of making the trailer skid.

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  1. In normal driving, some drivers use the hand valve before applying the brake pedal to prevent a jackknife. Which of these statements is true?
  2. You should not back a tractor under a trailer until the whole air system is:
  3. After you supply air to the trailer, make sure the airlines are not crossed and the trailer brakes are working. This can be done by:
  4. What is the safest way for you to make a turn without entering another traffic lane?
  5. Even before antilock braking systems (ABS) were required, some vehicles already had them. How can you check if your vehicle has ABS?
  6. What is the emergency air line?
  7. You are uncoupling a trailer. After you shut off the trailer air supply and lock the trailer brakes, you should
  8. A tractor with a(n) _______ trailer requires the shortest amount of stopping distance.
  9. The tractor protection valve will close and the trailer _______ brakes will come on when there is a major leak in the brake line.
  10. You have a major leak in the service line, and you put on the brakes. Service air pressure will escape and cause the:
  11. Semi-trailers made before 1975 that are equipped with air brakes:
  12. How much space should be between the apron and fifth wheel after coupling?
  13. On a trailer, where is the yellow antilock brake (ABS) malfunction lamp located?
  14. What are the other names for the service air line?
  15. You should not back a tractor under a trailer until the whole air system is
  16. Air and electrical lines from the tractor to the trailer should be
  17. Which of these statements is true?
  18. Which part of the kingpin should the locking jaws close around?
  19. Under good driving conditions, you should leave at least one second of space between your vehicle and the vehicle ahead for every ___ feet of your vehicle's length.
  20. You supply air to the trailer tanks by