Quiz 2 - Combination Vehicles

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

With the tractor frame under the trailer.
Completely cleared from the trailer.
With the fifth wheel directly beneath the kingpin.

2. Glad hands are usually connecting which of these?

Electric lines from the tractor to trailer.
Kingpin from the trailer to the locking jaws of the fifth wheel.
Service and emergency air lines from the vehicle to the trailer.

3. When driving a set of doubles it is necessary to close which shut-off valve in the last trailer.

Front
Middle section
Back

4. The air brake leakage rate for a combination vehicle (engine off, brakes off) should be less than _____psi per minute.

1/2
2
3
Back

5. You are about to back your tractor under a semi trailer. The trailer is at the right height when the:

Kingpin is about 1¼ inches above the fifth wheel.
End of the kingpin is even with the top of the fifth wheel.
Trailer will be lifted slightly when the tractor backs under it.

6. If the brakes are not released when you pushed the trailer air supply valve you should:

Check air line connection.
Cross the airlines.
Check electrical cable.

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

The shank.
Thehead.
The base.

8. 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?

The emergency and service air lines.
The electrical service cable.
Nothing. Back up and lock the fifth wheel.

9. You supply air to the trailer tanks by:

Pushing in the trailer air supply valve.
Pulling out the trailer air supply valve.
Connecting the service line glad hands.

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

To ensure a good electrical connection.
To prevent steering problems.
To reduce heat and noise.

11. When connecting the glad hands press the two seals with the coupler together at what degree to each other?

45 degree
90 degree
180 degree

12. Why should you lock the tractor glad hands to each other (or dummy couplers) when you are not towing a trailer?

The connected brake circuit becomes a back up air tank.
It will keep dirt or water out of the lines.
If you didn’t, you could never build system pressure.

13. Air and electrical lines from the tractor to the trailer should be:

Fully tight but away a little looped.
Secured but with enough loop to turn.
Resting on the frame of the tractor.

14. To stop a trailer skid you should:

Use the trailer hand brakes.
Release the service brakes.
Counter steer.

15. Compared to a straight truck or bus there are ______ things to inspect in combination vehicle.

Fewer
The same number
More



Correct of 15