Combination Flashcards
Which statement is true?
“Bobtail” tractors can take longer to stop than a combination vehicle loaded to maximum gross weight
After you connected the air lines, but before you back under the trailer, you should:
Supply air to the trailer system, then pull out the air supply
Under good driving conditions, you should leave at least one second of space between you vehicle and the vehicle ahead for every ___ feet of vehicle’s length
10 ft
You are coupling a tractor to a semitrailer. You have backed up but are not under it. What should you hook up before backing under the semitrailer?
The emergency and service air lines
Which part of the kingpin should the locking jaws close around?
The Shank
To stop a trailer skid you should:
release the brakes
When should you use chocks to park a trailer not equipped with spring brakes?
Always
You are uncoplig a trailer. After you shut off the trailer air supply and lock the trailer brakes, you should:
Back up jently to ease pressure on the fifth wheel locking jaws
To unlock the fifth wheel, put the release handle to the ___ position.
Open
Air and electric lines from the tractor to the trailer should be:
Secured, but with enough slack for turns
For a coupling to be completed, the safety lock for the fifth wheel locking lever must be:
over the locking lever
Why should you be sure that the fifth wheel plate is grased as required?
To prevent steering problems
You have pushed in the trailer supply valve. you should not move the tractor until the whole air system is:
At normal pressure
If you cannot make a turn without entering another traffic lane, you should:
Turn wide as you complete your turn
When coupling, the proper position of the ffth wheel is:
Tilted down towards the end of the tractor
A tractor with an ___ trailer requires the shortest stopping distance.
Fully loaded
After you lock the kingpin into the fifth wheel, you should check the connection by pulling:
The tractor ahead gently with the trailer brakes locked
In general, the higher you truck’s “center of gravity”the:
Easier it is to turn over
How much space should be between the upper and lower fifth wheel after coupling?
None
When checking that the trailer is securely to the tractor, the landing gear should be:
Slightly raised
You want to inspect thetrailer supports. You should place the tractor transmission in which gear after you have uncoupled the trailer?
Neutral
You are coupling a semitrailer to the tractor but have not backed under it. The trailer is at the right height when:
It is raised slightly when the tractor is backed under it
The front trailer supports are up and the trailer is resting on the tractor. Make sure:
There is enough clearance between the tractor frame and the landing gear
When checking the trailers emergency brakes, the tractor protection control valve should be placed in the ___ position
Emergency
There are two things that can prevent a rollover. They are: Keep the cargo as close to the ground as possible; and :
Go slow around turns
You should Not back a tractor under a trailer until the whole system air system is:
At normal pressure
The best way to tell if you trailer has started to skid is to:
See it in your mirrors
Which one of thesr vehicles off-track the most?
5-axle tractor towing a 52-foot trailer
Glad hands are used to connect the:
Service and the emergency air lines from the truck to the trailer
The fifth wheel locking lever is not locked after the jaws close around the kingpin. This means that:
The coupling is not right and should be fixed before driving th coupled unit.
A trailer is most likely to jackknife when it is:
Empty
If you have coupled with a semitrailer, where should the front trailer supports be before driving away?
Fully raised with the crack handle secured in its bracket
When you are uncoupling a loaded trailer, lower the landing gear until it:
makes firm contact with the ground and lifts the trailer off of the fifth wheel
Compared to a straight truck or bus, there are ___ things to inspect on a combination vehicle
More
To unlock he fifth wheel, pull the release handle to the ___ position
Open
Why should you lock the air line glad hands to each other (or dummy couplers) when you are not towing a trailer?
It will keep water out of the lines
After you have coupled the trailer, you should begin raising the landing gear by using the ___ gear
Low
After the trailer has been coupled to the tractor, the tractor protection control valve should be placed in the ___ position
Normal
Why should yo be sure that the fifth wheel plate is greased as required?
To prevent steering problems
After you supply air to the trailer, make sure the air lines are not crossed the trailer brakes are working. you do this by:
Applying/releasing the trailer brakes and listening for brake sounds
when you get ready to back under a semitrailer, you should line up:
Directly in front of the trailer
After you lock the kingpin into the fifth wheel, you should check the connectiong by pulling:
The tractor ahead gently with the trailer brakes locked
If you cannot male a turn without entering another traffic lane, you should:
Turn wide as you complete you turn
When backing a tractor under a trailer you should:
Always use the lowest reverse gear
Before you back under a truck trailer, make sure the:
Trailer brakes are on
