Glad hands are used to connect the:
Electric lines from the truck to the trailer
Kingpin from the tractor to the locking jaws on the glide plate
Service and emergency air lines from the truck to the trailer
. The trailer air supply control (or tractor protection valve control) should automatically close when the air pressure falls to between____ psi
20 and 45
60 and 85
100 and 125
If you cannot make a tum without entering another traffic lane, you should:
Turn wide before you start your turn
Turn wide as you complete your turn
Not make that turn
If the spring brakes dont release when you push the trailer air supply control, you should:
Check the air Iines connections
Cross the air Ines
Check the electriIcal service cable
The front trailer supports are up and the trailer is resting on the tractor. Make sure:
There Is enough clearance between the upper and lower fifth wheel
The safety latch is in the unlocked posltlon .
There Is enough clearance between the tractor frame and landing gear
There is enough clearance between the tops of the tractor tires and the nose of the trailer
A and B are correct,
You supply air to the trailer tanks by
Pushing In the trailer air upply valve
Pulling out the trailer air suppIy valve
Connecting the service line gland
A driver crosses the air lines when hooking up to an trailer with no spring brakes. What will happen?
The hand valve will apply the tractor brake not the trailer brakes
The brake pedal will work the trailer spring brakes not the air brakes
The driver could drive away with no trailer brakes
Which part of the kingpin should the locking' jaws close around?
When coupling, the proper position of the fifth wheel is:
Level with the ground
Tilted up towards the end of the tractor
Tilted down towards the end of the tractor
To unlock the fifth wheel, pull the relead handle to the position.
Before you back under a truck trailer, make iure the:
Trailer brakes are locked
Air supple know is in
Air brakes are off
After you connect the air Iines, but before you back under the trailer, you should:
Make sure the traile rakes are off
Walk around the rig to be sure it is clear
Supply air to the trailer system, then pull out the air supply knob
After you lock the kingpin into the fifth wheel, you should check the connection by pulling:
Forward 50 feet, turning right, and left
The tractor ahead sharply to release the trailer brakes
The tractor ahead gently with the trailer brakes locked
When should you use the hand valve park a combination vehicle
To park at loading docks
To park on a grade
The best way to tell if your trailer has started to skid to:
Hear the wheels skidding
See It In your mIrrors
Feel for "pulling" in the cab
You are uncoupling a trailer. After you shut off the trailer air supply and lock the trailer brakes, you should:
Back up gently to ease pressure on the fifth wheel locking jaws
Begin to lower the trailer landing gear
Immediately put on your tractor parking brakes
Why should you be sure that the fifth whee plate Is greased as required?
To ensure good electrical connections
To prevent steering problems
To reduce heat and noise
For a coupling to be complete, the safety catch for the fifth wheel locking lever must be:
Through the locking lever
Over the locking lever
What will happen if the air lines are crossed when you hook up to an old trailer with no spring brakes
the hand vlave applles the tractor brakes instead of the trailer brakes
you could drive away with not trailer brakes
the brakes lights will not come on when you press the brake pedal
One the things a driver can do to prevent a rollover is to keep:
Both hands firmly on the steering wheel
the cargo has closed to the ground as possible
The fifth wheel free play as small as possible
To stop a trailer skid, you should:
Use the trailer hand brake
Release the service brakes
You have pushed in the trailer supply valve. You should not move the tractor until the whole air system is:
At normal pressure
Between 60 and 80 psi
When you get ready to back under under a trailer you should line up:
The left rear outside dual wheel with the kingpin
The kingpin with the edge of the drivers side locking jaw
Directly in front of the trailer.
A trailer is most likely to jackknife when it is
Loaded to full capaclty
You have a major leak in the service line and you put on the brakes. Service air pressure will escape and cause the:
Trailer emergency brakes to come on
Trailer tank pressure to be lost
Tractor spring brakes to lock on
The air leakage rate for a combination of two vehicles (engine off, brakes off) should not be greater than_______psi per minute.
loss of air pressure in the emergency line causes:
the relay valves to close
An increase in air pressure to the service line
the trailer´s emergency brakes to come on
To prevent a jackknife in normal driving, some drivers use the hand valve before stepping on the brake pedal. Which of these statements is true?
It should not be done
It results in less skidding than using the brake pedal alone
it is the best way to brake and keep the truck in a straight line
A tractor with a(n)________trailer requires the shortest stopping distance
In general, the higher your truck´s center of gravity, ''the:
Easler it is to turn around comers
More stable it is when turning
Easier it is to turn over
Which of these statements is true?
The brake and suspension system of combination vehicles work best with a light load
Light vehicles need more braking power to stop than heavy ones.
"bobtail" tractors can take longer to stop than a combination vehicle
When should you use chocks to park a trairles not equipped with spring brakes?
Only when it will be parked on an incline
After you supply air to the trailer, make sure the air lines are not crossed and The trailer brakes are working. This is done by:
Turning on the parking brakes from the cab
Watching your mirrors to see if the trailer lights come on
Applying and releasing the trailer brakes and listening for brake sounds.
You are coupling a tractor to a semi trailer. 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.
The electrical service cable.
Nothing, back up and lock the fifth wheel.
You have uncoupled a trailer and you want to inspect the landing gear. the tractor should be positioned:
With the tractor frame under the trailer
Completely clear of the trailer
With the fifth wheel directly beneath the kingpin
When you are uncoupling a loaded trailer, lower the landing gear until it:
Makes firm contact with the ground
Makes contact with the groudn and lifts the trailer off of the fift wheel
Just reaches the ground
Under good driving conditions, you should leave at least one second of space between your vehicle and the vehicle ahead for avery_____feet of your vehicles length
You are coupling a tractor to a semi trailer to your tractor but have not yet backed under it. The trailer is at the right height when:
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 tractor is backed under it.
The tractor protection valve will close and the trailer emergency brakes will come on when there is a major leak in the____brake line
You are driving a combination vehicle. If the service air line comes apart but the emergency line stays together, what will happen right away?
The trailers air tank will exhaust through the open line
The emergency traller brakes will come on
Nothing is likely to happen until you try to apply the brakes
After the trailer has been coupled to the tractor, the tractor protection control valve should be placed in the________position.
You should not back a tractor under a trailer until the whole air system is:
When checking the trailer's emergency brakes, the tractor protection control valve should be placed in the ____ position.
You are driving a combination vehicle. The trailer breaks away and pulls apart both air lines. You would expect the trailer brakes to come on and the:
Tractot to lose all air pressure
Trailer supply valve to stay open
tractor protection valve to close
You want to inspect the trailer supports. You should place the tractor transmission in wich gear afet you have uncoupled the trailer?
Why should you lock the tractor glad hands (or dummy couplers) to each other when you are not towing a trailer?
The connected brake circuit becomes a back up air tank
It will keep water out of the lines
If you do not, you could never build system pressure
When backing under a tractor under a trailer you should expect:
Trailer will be lifted slightly when the tractor backs under it.
always approach the trailer at a slight angle
do it quickly to ensure that the kingpin is locked into the fifth wheel
after you have coupled the trailer, you should begin raising the landing gear by using the ___gear
There are two things that can prevent a rollover, they are 1) keep the cargo as close to the ground as possible, and 2)
make sure the brakes are properly adjusted
Keep both hands firmly on the steering wheel
Go slow around turns
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
if you have coupled with a semitrailer, where should the front trailer supports be 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 lot is off and may drive away
The coupling is not right and should be fixed before driving the vehicle.
compared to a straight truck or bus there are ____things to inspect on a combination vehicle
he same amount
How much space should be between the upper and lower fifth wheel after coupling?
about 1/4 inch
just enough to see light through it
Air lines on a combination vehicle are often colored to keep them from getting mixed up. The emergency line is ____; the service line is ____.
Depends on the type of trailer
How should you test the tractor semi trailer connection for security?
Pull gently forward in low gear against the locked trailer brakes, then look at it carefully.
Put the tractor in gear and pull ahead with a sharp jerk.
Rock the trailer back and forth with the trailer brakes locked.
Don't worry. The connection should be fine.
If the service air line comes apart while you are driving a combination vehicle but the emergency line stays together, what will happen right away?
Nothing is likely to happen until you try to apply the brakes.
The trailer's air tank will exhaust through the open line.
The emergency tractor brakes will come on.
In normal driving, some drivers use the hand valve before applying the brake pedal to prevent a jackknife. Which of these statements is true?
It results in less skidding than using the brake pedal alone.
It should not be done.
It is the best way to brake and keep the truck in a straight line.
The safety catch for the fifth wheel locking lever must be ____ for a coupling to be complete.
Under the locking lever
Over the locking lever
Semi trailers made before 1975 that are equipped with air brakes:
Often do not have spring brakes.
Usually need a glad hand converter.
Are easier to brake because they are heavier
You are coupling a tractor and semi trailer and have connected the air lines. Before backing under the trailer, you should:
Make sure that the trailer brakes are off.
Supply air to the trailer system, then pull out the air supply knob to lock the trailer brakes.
Apply the brakes twice to alert others.
Which of these statements about stopping distance and speed is true?
You need about two times as much stopping distance at 40 mph as at 20 mph
Wet roads can double stopping distance at any speed
Att 55 mph, it will take about 10 seconds to stop your vehicle
Before loading, unloading, or driving a tanker, the first thing you should do is
Properly secure all of the bafles
Inspect the vehicle
Make sure the tanker is properly placarded
The best way to drive through a curve is to slow to a safe speed before entering the curve and then______ as you go through it.
Wich of these statements is true about emergency steering?
A move to your right may be best, if a oncoming driver drifts into your lane
You can always stop more quickly tan you can steer to avold a hazard
You can steer more quickly and safely with one hand tan with two
The hand valve should be used:
Only with a foot brake.
To test the trailer brakes
As a parking brake.
When driving a set of doubles it is necessary to close which shut-off valve in the last trailer
You are about to back your tractor under a semitrailer. The trailer is at the right height when the:
Kingpin is about 1 1/4 inches above the fifth wheel.
End of the kingpin is even with the top of the fifth wheel
When connecting the glad hands press the two seals with the coupler together at what decree to each other?
Off-tracking or cheating causes of which of these to follow the wider pass while making a turn?
Tractor towing a 45-feet trailer
Tractor with two 27-feet trailers
The iron trailer supports are up and the trailer is resting on the tractor. Make sure:
There is enough clearance between the upper and lower fifth wheels
The safety latch is in unlocked position.
There is enough clearance between the tractor frame and the landing gear
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