Combination Vehicles Test Sect. 2

Front 1

1. Glad hands are used for connecting the:

Back 1

Service and emergency air lines from the truck to the trailer.

Front 2

2. Why should you be sure the fifth wheel plate is greased as required?

Back 2

To prevent steering problems.

Front 3

3. After connecting the airlines but before backing under the trailer, you should:

Back 3

Supply air to the trailer system, then pull out the air supply knob

Front 4

4: The trailer air supply control (also called the tractor protection valve control) should automatically close when the air pressure falls between.

Back 4

20 and 45 PSI

Front 5

5. When coupling, the proper position of the 5th is:

Back 5

Tilted down towards the end of the tractor

Front 6

6. Which part of the kingpin should the locking jaws close around?

Back 6

The shank

Front 7

7. A trailer is most likely to jack knife when it is:

Back 7

Empty

Front 8

8. If the spring brakes don't release when you push the trailer air supply control, you should:

Back 8

Check the air line connections.

Front 9

9. The best way to tell if your trailer has started to skid is to:

Back 9

See it in your mirrors

Front 10

10. To unlock the 5th wheel, pull the release handle to the ____ position

Back 10

Open

Front 11

11. When should you use the hand valve to park a combination vehicle?

Back 11

Never

Front 12

12. A driver crossed the airlines when hooking up to an old trailer. What happened?

Back 12

If the trailer has no spring brakes, they could drive away but wouldn't have trailer brakes.

Front 13

13. You supply air to the trailer tanks by:

Back 13

Pushing in the trailer air supply valve

Front 14

14. The front trailer supports are up and the is resting on the tractor. Make sure:

Back 14

There is enough clearance between the tractor and the landing gear

Front 15

15. Safety catch for the 5th wheel locking lever must be ___ for a coupling to be complete.

Back 15

Over the locking lever

Front 16

16. After you supply to the trailer, make sure the airlines are not crossed and the trailer brakes are working. This is done by:

Back 16

Applying and releasing the trailer braiges and listening for brake sounds.

Front 17

17. If the service line comes apart while you are driving a combination vehicle but the emergency line stays together, what will happen right away?

Back 17

Nothing is likely to happen until you try to apply the brakes

Front 18

18. Where should the tractor be when you inspect the landing gear after uncoupling the trailer?

Back 18

With the tractor frame under the trailer

Front 19

19. What gear should the tractor transmission be in after you have uncoupled the trailer and are inspecting the trailer supports?

Back 19

Neutral

Front 20

20. You should not back a tractor under a trailer until the whole air system is

Back 20

At normal pressure

Front 21

21. Which of these statements is true?

Back 21

"Bobtail" tractors can take longer to stop a combination vehicle loaded to maximum gross weight.

Front 22

22. You are coupling a semi-trailer to your tractor but have not yet backed under. The trailer is at the right height when:

Back 22

It will be raised slightly when the tractor is backed under it

Front 23

23. When you are uncoupling a loaded trailer, you should lower the landing gear until it:

Back 23

Makes firm contact with the ground, Nd then crank it in lower gear a few extra turns

Front 24

24. In general, the higher the center of gravity of your truck, the:

Back 24

Easier it is to turn over

Front 25

25. To be safe when driving behind other vehicles under good conditions, you should leave at least 1 second between your vehicle and the vehicle ahead for each ___ feet of your vehicles length.

Back 25

Ten

Front 26

26. You are coupling a tractor to a semi-trailer and have backed up but are not under it. What should you hook up before backing under?

Back 26

The emergency and the service air lines.

Front 27

27. A tractor with a ___ trailer requires the shortest amount of stopping distance.

Back 27

Fully loaded

Front 28

28. When checking the trailers emergency brakes, the tractor protection control valve should be placed in the ___ position.

Back 28

Emergency

Front 29

29. When do you need to use chocks to park a trailer that does not have spring brakes?

Back 29

Always

Front 30

30. You are driving a combination vehicle when the trailer breaks away, pulling apart both air lines. You would expect the trailer brakes to come on, and:

Back 30

The tractor protection valve to close.

Front 31

31. When you get ready to back under a trailer, you should line up:

Back 31

Directly in front of the trailer

Front 32

32. To stop a trailer skid, you should

Back 32

Release the service brakes

Front 33

33. The air leakage rate for a combination of two vehicles (engine off, brake off) should not be greater than

Back 33

3 PSI per minute

Front 34

34. Before you back under a trailer make sure the:

Back 34

Trailer brakes are locked.

Front 35

35. There are 2 things a driver can do to prevent rollover. 1) Go slow around turns and 2)

Back 35

Keep the cargo as close to the ground as possible

Front 36

36. After the trailer has been coupled to the tractor, the tractor protection control valve should be placed in the ___ position

Back 36

Normal

Front 37

37. When uncoupling a trailer, after you have shut off the trailer air supply and locked the trailer brakes, you should

Back 37

Back up gently to ease pressure on the 5th wheel locking jaws.

Front 38

38. After you lock the kingpin into the 5th wheel, you should check the connection by:

Back 38

Pulling the tractor ahead gently with the trailer brakes locked

Front 39

39. If you cannot make a turn without entering another traffic lane, you should:

Back 39

Turn wide as you complete your turn

Front 40

40. Loss of air pressure in the emergency line causes

Back 40

The trailer's emergency brakes to come on

Front 41

41. In normal driving, some drivers use the hand valve before the brake pedal to prevent a jack knife. Which statement is true?

Back 41

It should NOT be done

Front 42

41. In normal driving, some drivers use the hand valve before the brake pedal to prevent a jack knife. Which statement is true?

Back 42

It should NOT be done

Front 43

42. The tractor protection valve will close and the trailer emergency brakes will come on when there is a major leak in the ___ brake line.

Back 43

Emergency

Front 44

43. You have a major leak in the service line and you put on the brakes. Service air pressure will escape Nd cause the

Back 44

Trailer emergency brakes to come on

Front 45

44. What will happen if the airlines are crossed when you hook up to an old trailer?

Back 45

If the trailer has no spring brakes, you could drive away but you would not have trailer brakes.

Front 46

45. You have pushed in the trailer supply valve. You should not move the tractor until the whole air system is

Back 46

At normal pressure

Front 47

46. After you have coupled the trailer, you should begin raising the landing gear by using the ___ gear

Back 47

Low

Front 48

47. Why should you lock the airline glad hands to each other ( or keep dummy couplers) when you are not towing trailer?

Back 48

It will keep the water out of the lines.

Front 49

48. You want to inspect the trailer supports l. You should place the tractor transmission in which gear after you have uncoupled the trailer?

Back 49

Neutral

Front 50

49. When checking that the trailer is securely coupled to the tractor, the landing gear should be

Back 50

Slightly raised

Front 51

50. How much space should be between the upper and lower 5th wheel after coupling?

Back 51

None

Front 52

51. Which of these vehicles off-track the most?

Back 52

5-axle tractor towing a 52-foot trailer.

Front 53

52. If you have coupled with a semi-trailer, where should the front trailer supports be prior to driving away?

Back 53

Fully raised with crank handle secured in its bracket

Front 54

53. The 5th wheel locking lever is not locked after the jaws close around the king pin. This means that

Back 54

The coupling is not right and should be fixed before driving the coupled unit

Front 55

54. Compared to a straight truck or bus, there are ___ things to inspect on a combination vehicle.

Back 55

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