1. When coupling, the proper position of the fifth wheel is:
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Level with the ground.
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Tilted up toward the end the tractor.
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Tilted down toward the end the tractor.
2. Where should the tractor be when you inspect landing gear after un-coupling the trailer?
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With the tractor frame under the trailer.
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Completely cleared from the trailer.
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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:
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Check air line connections.
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Cross the air lines.
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Check the electrical service cable.
4. The safety catch for the fifth wheel locking lever must be ________ for a coupling to be complete.
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over the locking lever
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straight up
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through the locking lever
5. Off-tracking or "cheating" causes which of these to follow the widest path while making a turn?
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5-axle tractor towing a 45 feet trailer.
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5-axle tractor towing two 27 feet trailers.
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A bobtail.
6. When you are uncoupling a loaded trailer, you should lower the landing gear until it:
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Makes firm contact with the ground, then crank it in low gear a few extra turns.
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Make contact with the ground and lifts the trailer off of the fifth wheel.
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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:
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Trailer emergency brakes to come on.
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Trailer tank pressure to be lost.
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Tractor spring brakes to lock on.
9. You will know if the trailer you are driving has antilock brakes by:
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Yellow ABS malfunction lamps on the left side of the trailer.
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Red malfunction lamps on the trailer brake cylinders.
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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?
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Raised 1/2 way with the crank handle secured in its bracket.
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Fully raised with the crank handle secured in its bracket.
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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):
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Keep both hands firmly on the steering wheel.
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Keep the cargo as close to the ground as possible.
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Make sure that the brakes are properly balanced.
12. When you get ready to back under a semitrailer you should line up:
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The kingpin to engage the driver's side locking jaw first.
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Directly in front of the trailer.
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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:
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Fully raised.
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Slightly raised.
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Fully lowered.
14. You are about to back your tractor under a semitrailer. The trailer is at the right height when the:
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The kingpin is about 1 1/4 inches above the fifth wheel.
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The end of the kingpin is even with the top of the fifth wheel.
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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:
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Easier it is to turn around corners.
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More stable it is when turning.
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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:
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Level with the ground.
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Tilted down toward the end of the trailer.
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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:
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Back up gently to ease pressure on the fifth wheel locking jaws.
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Immediately put on your tractor parking brakes.
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Begin to lower the trailer landing gear.
19. When backing a tractor under a trailer you should:
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Always use the lowest reverse gear.
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Always approach the trailer at a slight angle.
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Do it quickly to ensure that the kingpin is locked into the fifth wheel.
20. To stop a trailer skid you should:
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Use the trailer hand brakes.
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Release the service brakes.
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Countersteer.
21. The trailer air supply control valve should automatically close when air pressure falls to between _______ psi.
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20 and 45
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60 and 85
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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 ________;
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red, blue
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black, yellow
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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:
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The trailer supply valve to stay open.
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The tractor to lose all air pressure.
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The tractor protection valve to close.
26. To unlock the fifth wheel the locking lever should be placed in the _____ position.