Combination Vehicle

Question 1

1) You supply air to the trailer tanks by:

Answer 1

pushing in the trailer air supply valve

Question 2

2) Loss of air pressure in the emergency line causes:

Answer 2

the trailer’s emergency breaks to come on

Question 3

3) A tractor with a ____________ trailer requires the shortest amount of stopping distance.

Answer 3

fully loaded

Question 4

4) Which of these statements is true?

A. the brake and suspension of combination vehicles work best with a light load
B. light vehicles need more braking power to stop than heavy ones
C. bobtails tractors can take longer to stop than fully loaded combination

Answer 4

C. Bobtails tractors can take longer to stop than a fully loaded vehicle.

Question 5

5) If you cannot make a right turn without swinging into another lane, you should:

Answer 5

turn wide as you complete the turn

Question 6

6) The tractor protection valve will close and the emergency brakes will come on when there is a major leak in what air line?

Answer 6

Emergency

Question 7

7) Off tracking or “cheating” causes which of these to follow the widest path while making a turn?

Answer 7

3 axle tractor towing a 45 foot trailer

Question 8

8) If your vehicle gets stuck on a railroad crossing, you should:

Answer 8

get out of the vehicle and away from the tracks

Question 9

9) When driving a set of double trailers, it is necessary to close shut-off valves on some trailers. Where are these valves located?

Answer 9

At the back of trailers used to tow other trailers

Question 10

10) Before you back under a trailer, make sure of what?

Answer 10

The trailer brakes are locked

Question 11

11) To unlock the fifth wheel, you pull the handle to what position?

Answer 11

Open

Question 12

12) After connecting the air lines, but before backing under the trailer, you should:

Answer 12

supply air to the trailer, then pull out the trailer air supply valve

Question 13

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

Answer 13

The emergency and service air lines

Question 14

14) You are coupling a tractor to a trailer. The trailer is at the right hight when:

Answer 14

the trailer is raised slightly when the tractor is backed under it

Question 15

15) Why should you connect the air lines to a dummy coupler when they are not in use?

Answer 15

It will keep dirt and water out of the lines

Question 16

16) The air leakage rate for a combination vehicle engine with the engine offand the brakes off should be less than?

Answer 16

3 PSI

Question 17

17) Air and electric lines from the tractor to the trailer should be:

Answer 17

secured properly with enough slack for turns

Question 18

18)Air brake equipped trailers made before 1975:

Answer 18

often do not have spring brakes

Question 19

19) The hand valves should be used:

Answer 19

to test the trailer brakes

Question 20

20) The air leakage rate for a combination vehicle with the engine off and the brakes on should be less than _____ per minute.

Answer 20

4 PSI

Question 21

21) Your emergency line brakes or gets pulled apart while driving. The loss of pressure will cause the:

Answer 21

emergency trailer brakes to come on

Question 22

22) You have pushed in the trailer air supply valve. You should not move the vehicle until the whole system is:

Answer 22

at normal pressure

Question 23

23) When should you use the hand valve to park a combination vehicle?

Answer 23

Never

Question 24

24) The best way to tell that your trailer has started to skid is to:

Answer 24

see it in your mirrors

Question 25

25) A trailer is most likely to jackknife when it is:

Answer 25

empty

Question 26

26) If the service line comes apart but the emergency line stays together, what will happen right away?

Answer 26

Nothing is likely to happen until you apply the brakes

Question 27

27) When backing a tractor under a trailer you should:

Answer 27

always use the lowest reverse gear

Question 28

28) After you have coupled the trailer, you should begin raising the landing gear using what gear?

Answer 28

Low gear

Question 29

29) You will know the trailer you are using has ASB by:

Answer 29

a yellow malfunction lamp on the left side

Question 30

30) If you cross the air lines while coupling to an old trailer what will happen?

Answer 30

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

Question 31

31) When should you get out of your vehicle when you are backing a trailer?

Answer 31

When you are unsure of your path of travel

Question 32

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

Answer 32

Makes firm contact with the ground, then turn it a few extra cranks in lower gear

Question 33

33) How much space should be between the upper and lower fifth wheel after coupling?

Answer 33

None

Question 34

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

Answer 34

the is enough clearance between the frame and the landing gear

Question 35

35) Why should you be sure the the fifth wheel is greased as required?

Answer 35

To prevent steering problems?

Question 36

36) After you lock the kingpin into the fifth wheel, you check the connection by:

Answer 36

pulling the tractor ahead gently with the trailer brakes locked

Question 37

37) After you supply air to the trailer, make sure the lines are not crossed and the brakes are working. This is done by:

Answer 37

applying and releasing the trailer brakes and listening for sounds

Question 38

38) To be safe while driving, you should at least leave 1 second for every __ feet of vehicle length as following distance.

Answer 38

10

Question 39

39) Two things you can do to prevent rolling over are keep the cargo as low to the ground as possible, and:

Answer 39

go slow around turns

Question 40

40) You have a major leak in the service line and you put on the brakes. Service air pressure will escape and if it goes low enough will cause:

Answer 40

trailer emergency brakes to come on

Question 41

41) When uncoupling a trailer, after you have locked the trailer brakes, you should:

Answer 41

back up gently to ease pressure on the fifth wheel jaws

Question 42

42) When do you need to use chokes to park a trailer that does not have spring brakes?

Answer 42

Always

Question 43

43) The fifth wheel locking lever is not locked after the jaws close around the kingpin. This means:

Answer 43

The coupling is not right and should be fixed before driving.

Question 44

44) When you get ready to back under a trailer, you should line up:

Answer 44

directly in front of the trailer

Question 45

45) After you have coupled to a trailer, the tractor protection valve should be placed in the ______ position.

Answer 45

normal

Question 46

46) How should you test the trailer connection for security?

Answer 46

Pull gently forward with the trailer brakes locked, then look at it carefully

Question 47

47) The trailer air supply valve should automatically close when air pressure falls to what range?

Answer 47

20-45 PSI

Question 48

48) What part of the kingpin should the jaws be locked around?

Answer 48

The shank

Question 49

49) The higher your center of gravity of your truck, the:

Answer 49

easier it is to turn over

Question 50

50) When checking that the trailer is securely coupled to the tractor, the landing gear should be:

Answer 50

slightly raised

Question 51

51) If you must back your trailer on a curved path, you should position your vehicle so you can back:

Answer 51

to the driver’s side

Question 52

52) If your ASB is not working on your trailer, you should:

Answer 52

drive normally, but get the system serviced soon

Question 53

53) Compared to a straight truck or bus, there are ____ things to inspect on a combination vehicle.

Answer 53

More

Question 54

54) Air lines are often colored. The emergency line is? The service line is?

Answer 54

Red, blue.

Question 55

55) To stop a trailer skid you should:

Answer 55

release the service brake

Question 56

56) What gear should the transmission be in after you have uncoupled and are inspecting the trailer supports?

Answer 56

neutral

Question 57

57) You have coupled to a trailer. Where should the landing gear be before driving away?

Answer 57

Fully raised with the crank handle secured in the bracket