Combination Flashcards
When should you use the hand valve to park a combination vehicle?
a. Never
b. To park at loading docks
c. To park on a grade
Never
Semitrailers made before 1975 that are equipped with air brakes:
a. often they don’t have spring brakes
b. usually need glad hand converter
c. they have only one air service line
often they don’t have spring brakes
The hand valve should be used:
a. only with the foot brake
b. to test the air brakes
c. like a parking brake
to test the air brakes
The best way to verify whether your truck has started to skid is by:
a. feel a pull in the cab
b. looking through your mirrors
c. hear the wheels skid
looking through your mirrors
How much space should be between the upper and lower fifth wheel after coupling?
a. approximately 1/4 of an inch
b. just enough to see light through it
c. none
none
Air and electric tractor lines should be:
a. firmly pulled, with very little loose parts
b. over the tractor structure
c. secured in place, but make sure it will be loose enough when it makes turns
secured in place, but make sure it will be loose enough when it makes turns
When unlock the fifth wheel, pull the release handle to:
a. close position
b. neutral position
c. open position
open position
You have coupled with a semitrailer. In what position should you put the front trailer supports before driving away?
a. raised (1/2) way with the crank handle secured in its bracket
b. raised 3/4 with the crank handle removed
c. fully raised with the crank handle secured in its bracket
fully raised with the crank handle secured in its bracket
You are coupling a tractor and semitrailer, and have connected the air lines. Before backing under the trailer, you should:
a. make are that the trailer brakes are off
b. supply air to the trailer system, then pull out the air supply knob to lock the trailer brakes
c. move forward to test the glad hands
supply air to the trailer system, then pull out the air supply knob to lock the trailer brakes
You are coupling a tractor to a semitrailer and have backed up but are not under it. What should you hook up before backing under?
a. the electrical service cable
b. nothing: back up and lock the fifth wheel
c. the emergency and service air lines
the emergency and service air lines
In general, the higher the gravity center of your truck the:
a. easier to make a turn at the corner
b. easier to rollover
c. more stable when you take a turn
easier to rollover
When you driving a set of doubles, it’s necessary to:
a. shut off valve at front of the last trailer
b. shut off valve in the middle of the last trailer
c. shut off valve at the rear of the last trailer
shut off valve at the rear of the last trailer
If the air lines cross over when hooking up to an old trailer, what will happen?
a. if the trailer has no spring brakes, you can drive away, but you would not have trailer brakes
b. the hand valve will apply the tractor brakes instead of the trailer brakes
c. the brake lights won’t turn on, when you put on the brake pedal
if the trailer has no spring brakes, you can drive away, but you would not have trailer brakes
Which of these statements is true?
a. the brake systems and the combination vehicle suspension will work better with a light weight
b. light vehicles need more braking power to stop than heavy ones
c. Bobtail tractors can take longer to stop than combination vehicles loaded to the maximum gross weight
Bobtail tractors can take longer to stop than combination vehicles loaded to the maximum gross weight
When you lock the kingpin to the fifth wheel, you should check the couple by
a. pulling the tractor forward, slightly with the trailer brakes on
b. pulling the tractor forward, a sharpness way to release the trailer brake
c. pulling forward 50 feet, then turning right and left
pulling the tractor forward, slightly with the trailer brakes on
You have pushed the trailer supply valve. you should not move a tractor until the whole air system is:
a. at normal pressure
b. between 60 and 80 psi
c. empty
at normal pressure
When you uncouple a trailer, after turning off the trailer air supply and putting on the trailer brakes, you should:
a. start down the trailer landing gear
b. back slowly, to decrease the pressure from the locking jaws of the fifth wheel
c. immediately put on the tractor parking brakes
immediately put on the tractor parking brakes
You supply air to the trailer tanks by:
a. connecting the service line glad hand
b. pushing in the trailer air supply valve
c. pulling out the trailer air supply valve
pushing in the trailer air supply valve
You are about to back your tractor under a semitrailer, the trailer is at the right height when the:
a. the kingpin is 1 & 1/4 over the fifth wheel
b. trailer will be lifted slightly when the tractor backs under it
c. end of the kingpin is even with top of the fifth wheel
trailer will be lifted slightly when the tractor backs under it
You should not back a tractor under a trailer until the whole air system is:
a. at normal pressure
b. between 60 psi and 80 psi
c. empty
at normal pressure
A tractor trailer combination has more probability to roll over on a curve, when the configuration includes:
a. a 45 feet trailer long and one 27 feet long
b. double trailers 45 feet long
c. triple trailers 27 feet long
triple trailers 27 feet long
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:
a. the trailer supply valve to stay open
b. the tractor protection valve to close
c. the tractor to lose all air pressure
the tractor protection valve to close
The tractor protection valve will close and the trailer emergency brakes will apply when there is a big leak in:
a. service brake line
b. parking brake line
c. emergency brake line
emergency brake line
If the spring brakes don’t release when you put on the trailer air supply control, you should:
a. cross the air lines
b. check air line connections
c. check the electric service cable
check air line connections
Why should you be sure that the fifth wheel plate is greased as required?
a. to prevent steering problems
b. to ensure good electrical connections
c. to reduce heat and noise
to prevent steering problems
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:
a. applying and releasing the trailer brakes, and listening for brake sounds
b. watch your mirrors to see if the trailer lights are turning on
c. turning on the parking brakes from the cab
applying and releasing the trailer brakes, and listening for brake sounds
Which is the fifth wheel position, before coupling to a trailer?
a. wheel tilted down towards front of tractor
b. wheel tilted down towards rear of tractor
c. wheel level
wheel tilted down towards rear of tractor
- **The air leakage for a combination vehicle (engine off, brakes off) should be less than:
a. 1/2 psi per minute
b. 3 psi per minute
c. 2 psi per minute
3 psi per minute
If you cannot make a turn without entering to another lane, you should:
a. make a wider turn when you complete the turn
b. don’t do that turn and ego to another place where you don’t have to cross lanes
c. make a wider turn before you begin turning
make a wider turn when you complete the turn
How should you test the tractor-semitrailer connection for security?
a. put the tractor in gear and pull ahead with a sharp jerk
b. pull gently forward in low gear against the locked tracker brakes, then look at it carefully
c. rock the trailer back and forth with the trailer brakes locked
pull gently forward in low gear against the locked trailer brakes, then look at it carefully
There are two things that a driver can do to prevent a roll over, they are: (1) Keep the cargo as close to the ground as possible and (2)…
a. hold with both hands the steering wheel firmly
b. go slowly around turns
c. make sure that the brakes are properly adjusted
go slowly around turns
When you connect the glad hands, press the two seals together with the couplers to:
a. 45 degree angle to each other
b. 180 degree angle to each other
c. 90 degree angle to each other
90 degree angle to each other
When pulling a tractor under a trailer, you should:
a. always use the lowest reverse gear
b. do it faster to make sure the kingpin is locked on the fifth wheel
c. always back under the trailer at a delicate angle
always use the lowest reverse gear
“Offtracking” or “Cheating” Which one will cause to follow the wider path when a vehicle goes around a corner?
a. a bobtail
b. 5 axles tractor pulling a 45 feet trailer
c. 5 axles tractor pulling two 27 feet trailers
5 axles tractor pulling a 45 feet trailer
What should you do to stop a trailer jackknife?
a. counter steer the steering wheel
b. use the trailer hand brake
c. release the service brakes
release the service brakes
You are coupling a semitrailer to your tractor but have not yet backed under. The trailer is at the right height when:
a. it will be raised sightly when the tractor is backed under it
b. the end of the kingpin is even with the top of the fifth wheel
c. the kingpin is about 1 & 1/4 inches above the fifth wheel
it will be raised slightly when the tractor is backed under it
For safe driving when you are behind other vehicles, in good driving conditions, you should keep at least 1 second between your vehicle and the front vehicle, by each:
a. 30 feet the long of your vehicle
b. 20 feet the long of your vehicle
c. 10 feet the long of your vehicle
10 feet the long of your vehicle
The safety catch for the fifth wheel locking lever must be:
a. through the locking lever for a coupling to be complete
b. over the locking lever for a coupling to be complete
c. right upward for a coupling to be complete
over the locking lever for a coupling to be complete
- **The air leakage rate for a combination vehicle (engine off, brakes on) should be less than:
a. 4 psi per minute
b. 2 psi per minute
c. 3 psi per minute
4 psi per minute
What gear must the tractor transmission be in after uncoupling a trailer when you are checking the landing gear?
a. neutral
b. lowest reverse gear
c. highest reverse gear
neutral
The glad hands are used to connect:
a. the electric lines from the truck to the trailer
b. the emergency and service lines from the vehicle to the trailer
c. the tractor kingpin to the locking jaws on the sliding plaques
the emergency and service lines from the vehicle to the trailer
You have a major leak in the service line and you put on the brakes, service air pressure will escape and cause the:
a. trailer tank pressure to be lost
b. tractor spring brakes to lock on
c. trailer emergency brakes to come on
tractor spring brakes to lock on
There are two things that a driver can do to prevent a roll over. They are: (1) go slowly around turns and (2)…
a. keep the fifth wheel’s free play as tight as possible
b. hold firmly with both hands the steering wheel
c. keep the cargo as close to the ground as possible
keep the cargo as close to the ground as possible
When you are uncoupling a loaded trailer you should down the landing gear until:
a. the landing gear makes firm contact with the ground, and turn crank in low gear a few extra turns
b. it makes contact with the ground and rises the trailer from the fifth wheel
c. It just makes contact with the ground
the landing gear makes firm contact with the ground, and turn crank in low gear a few extra turns
After you couple a trailer, you must begin to raise the landing gear using the:
a. high gear
b. low gear
c. medium level gear
low gear
When checking the trailer is safely coupled to the tractor the landing gear should be:
a. fully lowered
b. slightly raised
c. fully raised
slightly raised
A tractor with a:
a. loaded trailer with light cargo required the shortest distance to stop
b. empty trailer requires the shortest distance to stop
c. fully loaded trailer requires the shortest distance to stop
fully loaded trailer requires the shortest distance to stop
You should not back a tractor under a trailer until the whole air system is:
a. between 60 psi and 80 psi
b. at normal pressure
c. empty
at normal pressure
The fifth wheel locking lever is not locked after the jaws close around the kingpin. This means that:
a. the trailer doesn’t turn over the fifth wheel
b. the parking lock is off, and uno may drive away
c. the coupling is not right and should be fixed before driving the coupled unit
the coupling is not right and should be fixed before driving a coupled unit
The air supply valve or control valve protection, should close automatically when air pressure drops between:
a. 100 & 125 psi
b. 20 & 45 psi
c. 60 & 85 psi
20 & 45 psi
When do you need to use chocks to park a trailer without spring brakes?
a. always
b. when you are going too be parking on a steep downgrade only
c. never
always
When you get ready to back under the semitrailer you should line up:
a. the kingpin to engage the driver’s side locking jaw first
b. directly in front of the trailer
c. the external left back tire fold with the kingpin
directly in front of the trailer
A trailer is more probable to jackknife when:
a. it is fully loaded
b. it is empty
c. it is overloaded
it is empty
Before you back under a trailer, make sure the:
a. are brakes are off
b. trailer brakes are locked
c. tire supply knob is pushed in
trailer brakes are locked
Why should you lock the tractor glad hands (or dummy couplers) to each other when you are not rowing a trailer?
a. if you did not, you could never build up system pressure
b. it will keep dirt and water out of the lines
c. the connected brake circuit, beams a back up air tank
it will keep dirt and water out of the lines
When you check the trailer emergency brake, the tractor protection control valve should be replaced in:
a. neutral position
b. emergency position
c. normal position
emergency position
Where should the tractor be when you check the landing gear after you separate from a trailer?
a. with the tractor structure under the trailer
b. completely free of the trailer
c. with the fifth wheel under the king pin
with the tractor structure under the trailer
The trailer brake supports are lifted and the trailer is rising in the tractor. Make sure that:
a. there is enough space between the tractor structure and landing gear
b. the security safe is not on
c. there is enough space between the superior and inferior fifth wheel
there is enough space between the tractor structure and landing gear
What color are the air supply lines on a combination vehicle (emergency, service)
a. blue, red
b. red, blue
c. yellow, black
red, blue
Should you use the hand valve to control the vehicle?
a. do not do this
b. only when parking
c. when you go on a grade
do not do this
What color(s) are the air lines?
a. blue, red
b. yellow, black
c. blue, green
blue, red
When do you need to check more, on a pre-trip inspection?
a. in a combination vehicle
b. in a bus
c. it’s the same
in a combination vehicle
Which part of the kingpin should the locking jaws close around?
a. the shank
b. the head
c. the base
the shank
When you couple, the fifth wheel position is?
a. steep down at the end of the tractor
b. level on the ground
c. steep up at the end of the tractor
steep down at the end of the tractor
What will happen if the emergency air line breaks?
a. nothing happen
b. nothing happen until you use the brakes
c. loose all air pressure
nothing happen until you use the brakes
Which is the space between double tires?
a. 1/4
b. 1/2
c. 1/3
1/2
