Combination Vehicles - Quiz Sample #3, 15 questions
When should you use the hand valve to park a combination vehicle?
To park at loading docks.
To park on a grade.
Never.
When checking the trailer emergency brakes, the tractor protection control valve should be placed in the ________ position.
Emergenc
Normal
Neutral
What gear should the tractor be in after you uncouple from the trailer and are inspecting the trailer supports?
Neutral.
Low reverse.
High reverse.
You are uncoupling a trailer. After you shut off the trailer air supply and lock the trailer brakes, you should:
Begin to lower trailer landing gear.
Immediately put on your tractor parking brakes.
Back up gently to ease pressure on the fifth wheel locking jaws.
Combination vehicles are usually heavier, longer, and require more driving skill than single commercial vehicles.
True
False
More than half of truck driver deaths in crashes are the result of rollovers. Trucks turn over easier when fully loaded and are:
Two times more likely to roll over in a crash than empty rigs.
Five times more likely to roll over in a crash than empty rigs.
Ten times more likely to roll over in a crash than empty rigs.
When you turn suddenly while pulling doubles, which trailer is most likely to turn over?
The rear trailer is twice as likely to turn over as the tractor.
The front trailer is twice as likely to turn over as the tractor.
Each trailer is equally likely to turn over as the tractor.
Why should you not use the trailer hand brake to straighten out a jackknifing trailer?
Because the brake handle is too hard to reach.
Because the brakes on the trailer wheels caused the skid in the first place.
Because the brakes on the trailer wheels will not respond to the hand brake.
What is a tractor jackknife?
When you lock up the tires on the trailer and the trailer spins out sideways as the tractor continues to push forward.
When you lock up the drive tires on the tractor and the tractor spins out sideways as the trailer continues to push forward.
Neither of these answers are correct.
Why should you not use the trailer hand valve while driving?
Because it won’t work as well as the foot brake.
Because you should use the parking brake.
Because of the danger of making the trailer skid.
Describe what the trailer air supply control does:
It is used to supply the trailer with air, shut the air off, and put on the trailer emergency brakes.
It is a yellow, six-sided knob used to control the tractor protection valve.
It is a device used to keep the trailer behind the tractor.
Describe what the service line is for?
To carry air to the parking brake to control the trailer brakes.
To carry air to a relay valve that allows the trailer brakes to be applied quickly.
To carry air to the cab of the rig to cool it.
What are the other names for the service air line?
Control line or signal line.
Straight line or control line.
Curved line or signal line.
What is the emergency line?
Air lines connecting the parking brake to the trailer brakes.
Air lines that control the emergency brakes of the tractor.
Air lines that control the emergency brakes on combination vehicles.
What is the emergency air line for?
To engage the front brakes of the tractor in case of an emergency.
To engage the trailer brakes in case of an emergency.
To have extra air pressure in case you need it.
Why should you use chocks when parking a trailer without spring brakes?
Because you don’t want the trailer rolling down a hill.
Because if the air pressure leaks away or down, there will be no brakes.
Because some states require chocking of trailer wheels.
When a vehicle is carrying a load at night which extends four feet or more beyond the rear of the body, there must be _____ at the extreme end of the load.
2 red lights.
1 red flag.
2 red flags.
How long does it take a typical tractor-trailer to clear a single track? A double track?
It takes 10 seconds to clear a single track, and more than 12 seconds to clear a double track.
It takes 7 seconds to clear a single track, and more than 10 seconds to clear a double track.
It takes 14 seconds to clear a single track, and more than 15 seconds to clear a double track.
You have pushed in the trailer supply valve. You should not move the tractor until the whole air system is:
Empty.
At normal pressure.
Between 60 and 80 PSI.
The best way to tell if your trailer has started to skid is to:
Hear the wheels skidding.
See it in your mirrors.
Feel for “pulling” in the cab.
Which of these vehicles off-track the most?
5-axle tractor towing a 52-foot trailer.
5-axle tractor towing a 45-foot trailer.
5-axle tractor towing a 42-foot trailer.
A tractor with a(n) ____ trailer requires the shortest amount of stopping distance.
Empty
Lightly loaded
Fully loaded
If you have coupled with a semi-trailer, where should the front trailer supports be before driving away?
Raised 1/2 way with the crank handle secured in its bracket.
Raised 3/4 way with the crank handle removed.
Fully raised with the crank handle secured in its bracket.
The fifth wheel locking lever is not locked after the jaws close around the kingpin. This means that:
The trailer will not swivel on the fifth wheel.
The parking lock is off and may drive away.
The coupling is not right and should be fixed before driving the coupled unit.
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