CDL Combination Test
If you cross connect the two air lines the following will result - ✔✔You will not have air
going to the trailer brakes
You have coupled with a semi-trailer. In what position should you put the fro
...
CDL Combination Test
If you cross connect the two air lines the following will result - ✔✔You will not have air
going to the trailer brakes
You have coupled with a semi-trailer. In what position should you put the front trailer
supports before driving away? - ✔✔Fully raised with the crank handle secured in its
bracket
Th trailer air supply control: - ✔✔Is a red, eight sided knob
A device which connects the service and emergency air lines from the truck to the trailer
is called.. - ✔✔Glad hands
If one of the glad hands on your blue air line is missing a seal: - ✔✔You might end up
with a service line air leak
In order to supply air to the trailer, you must first: - ✔✔Stop engine so you can hear the
brakes
The hand valve should be used: - ✔✔To test the trailer brakes
The air leakage rate for a combination vehicle (engine off, brakes on) should not be
more than _______ psi per minute - ✔✔4
When should you use the hand valve to park a combination vehicle? - ✔✔Never
When you get ready to back under the semi-trailer you should line up - ✔✔Directly in
front of the trailer
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
When uncoupling, if you park the trailer at an angle... - ✔✔You could do damage to the
landing gear
Which of these statements is true? - ✔✔"Bobtail" tractors can take longer to stop than a
combination vehicle loaded to the maximum gross weight
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 should not be done
When you inspect the coupling, check to ensure that: - ✔✔There's a little slack in the air
lines
When backing under a tractor under a trailer you should expect: - ✔✔Trailer will be lifted
slightly when the tractor back under it
A king pin is: - ✔✔A pin which locks the trailer to the tractor on the fifth wheel
The safety catch for the fifth wheel locking level must be ______ for a coupling to be
complete. - ✔✔Over the locking lever
The air leakage rate for a combination vehicle (engine off, brakes off) should be no
more than _____ psi per minute. - ✔✔3
You are coupling a tractor to a semi-trailer and have backed up but are not under it.
What should you hook up before backing under? - ✔✔The emergency and service air
lines
Air lines on a combination vehicle are often colored to keep them from getting mixed up.
The emergency line is ____; the service line is _____. - ✔✔Red, blue
You should not back a tractor under a trailer until the whole air system is: - ✔✔At
normal pressure
Large combination vehicles take longer to stop: - ✔✔When they are empty
In order to inspect the coupling, you should: - ✔✔Use a flashlight if necessary
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: - ✔✔Applying and releasing the trailer brakes and
listening for brake sounds; and also by lifting the brake pedal
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 and that
there is enough clearance between the tops of the tractor tires and the nose of the
trailer
You can damage the landing gear if you: - ✔✔Back under the trailer at an angle
After you supply air to the trailer, make sure the airlines are not crossed and the trailer
brakes are working. This is done by: - ✔✔Applying and releasing the trailer brakes and
listening for brake sounds
When rolling up the landing gear to complete the coupling process: - ✔✔Grease the
landing gear to speed up the process
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): - ✔✔Go slowly around turns
Why should you be sure that the fifth wheel plate is greased as required? - ✔✔To
prevent steering problems
When coupling the glad hands, you should NOT do the following: - ✔✔Cross air supply
lines to test them for leaks
If one of the glad hands on your blue air line is missing a seal: - ✔✔You might end up
with a service line air leak
Before you back under a trailer, make sure the: - ✔✔Trailer brakes are locked
The driver crosses the air lines when hooking up to an old trailer. What will happen? -
✔✔If the trailer has no spring brakes, you can drive away, but you will not have trailer
brakes
You supply air to the trailer tanks by: - ✔✔Pushing the trailer air supply valve
You should crank the landing gear until: - ✔✔It is as far up as it will go
When uncoupling, it's generally good practice to: - ✔✔Couple the glad hands together;
Couple the glad hands to dummy couplers; Hag the electrical cable with the plug end
down
If you cross air lines on a new trailer with spring brakes: - ✔✔You won't be able to
release the trailer brakes
The earliest way to notice a trailer skid is: - ✔✔By seeing it in your mirrors
The trailer should be lowered so that: - ✔✔It's raised slightly when the tractor's backed
under it
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 the vehicle
To prevent rollovers, remember to : - ✔✔Keep the load centered, Keep the load as low
as possible, Go slow around turns
Which one of the following is controlled by the foot brake? - ✔✔The service air line
When coupling the trailer, back up slowly until: - ✔✔The fifth wheel touches the trailer
"Off-tracking" occurs when you go around a corner and: - ✔✔The rear wheels follow a
different path than the front wheels
You are coupling a semi-trailer to your tractor but have not yet backed under. The trailer
is at the right height when: - ✔✔It will be raised slightly when the tractor is backed under
it
Why should you lock the tractor glad hands (or dummy couplers) to each other when
they are not towing a trailer? - ✔✔It will keep dirt and water out of the lines
If you start a trailer skid you should: - ✔✔Release the brakes to get traction back
Which of the following steps
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