1. When coupling, the proper position of the fifth wheel is:
Level with the ground.
Tilted up toward the end the tractor.
Tilted down toward the end the tractor.
2. Where should the tractor be when you inspect landing gear after un-coupling the trailer?
With the tractor frame under the trailer.
Completely cleared from the trailer.
With the fifth wheel directly beneath the kingpin.
3. If the spring brakes don't release when you push the trailer air supply valve, you should:
Check air line connections.
Cross the air lines.
Check the electrical service cable.
4. The safety catch for the fifth wheel locking lever must be ________ for a coupling to be complete.
over the locking lever
straight up
through the locking lever
5. Off-tracking or "cheating" causes which of these to follow the widest path while making a turn?
5-axle tractor towing a 45 feet trailer.
5-axle tractor towing two 27 feet trailers.
A bobtail.
6. When you are uncoupling a loaded trailer, you should lower the landing gear until it:
Makes firm contact with the ground, then crank it in low gear a few extra turns.
Make contact with the ground and lifts the trailer off of the fifth wheel.
Just reaches the ground.
7. The air leakage rate for a combination vehicle (engine off, brakes on) should be less than _____ psi per minute.
8. You have a major leak in the service line and you put on the brakes. Service air will escape and cause the:
Trailer emergency brakes to come on.
Trailer tank pressure to be lost.
Tractor spring brakes to lock on.
9. You will know if the trailer you are driving has antilock brakes by:
Yellow ABS malfunction lamps on the left side of the trailer.
Red malfunction lamps on the trailer brake cylinders.
Yellow ABS malfunction lamps on the right side of the trailer.
10. You have coupled with a semitrailer. Where should you put the front trailer supports before driving away?
Raised 1/2 way with the crank handle secured in its bracket.
Fully raised with the crank handle secured in its bracket.
Raised 3/4 way with crank handle removed.
11. There are two things that a driver can do to prevent a rollover. They are: (1) Go slow around turns; and (2):
Keep both hands firmly on the steering wheel.
Keep the cargo as close to the ground as possible.
Make sure that the brakes are properly balanced.
12. When you get ready to back under a semitrailer you should line up:
The kingpin to engage the driver's side locking jaw first.
Directly in front of the trailer.
The left rear outer dual wheel with the kingpin.
13. While checking if the trailer is securely coupled to the trailer the landing gears should be:
Fully raised.
Slightly raised.
Fully lowered.
14. You are about to back your tractor under a semitrailer. The trailer is at the right height when the:
The kingpin is about 1 1/4 inches above the fifth wheel.
The end of the kingpin is even with the top of the fifth wheel.
It will be raised slightly when the trailer is backed under it.
15. In general, the higher the "center of gravity" of your truck, the:
Easier it is to turn around corners.
More stable it is when turning.
Easier it is to turn over.
16. After the trailer has been coupled to the tractor, the tractor protection control valve should be placed in _____ position.
17. When coupling, the proper position of the fifth wheel is:
Level with the ground.
Tilted down toward the end of the trailer.
Tilted up toward the end the trailer.
18. When uncoupling the trailer, after you have shut off the trailer air supply and locked the trailer brakes, you should:
Back up gently to ease pressure on the fifth wheel locking jaws.
Immediately put on your tractor parking brakes.
Begin to lower the trailer landing gear.
19. When backing a tractor under a trailer you should:
Always use the lowest reverse gear.
Always approach the trailer at a slight angle.
Do it quickly to ensure that the kingpin is locked into the fifth wheel.
20. To stop a trailer skid you should:
Use the trailer hand brakes.
Release the service brakes.
Countersteer.
21. The trailer air supply control valve should automatically close when air pressure falls to between _______ psi.
20 and 45
60 and 85
100 and 125
22. To unlock the fifth wheel, pull the release handle to the _______ position.
23. Air lines on a combination vehicles are often colored to prevent them from mixing up. The emergency line is________ ; the service line is ________;
red, blue
black, yellow
blue, red
24. When checking the trailer's emergency brakes, the tractor protection control valve should be placed in the _______ position.
25. 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:
The trailer supply valve to stay open.
The tractor to lose all air pressure.
The tractor protection valve to close.
26. To unlock the fifth wheel the locking lever should be placed in the _____ position.