NC CDL COMBINATION VEHICLES PRACTICE
EXAM 2026 QUESTIONS AND ANSWERS
SOLVED 100% CORRECT
◉ You should not back a tractor under a trailer until the whole air
system is: Answer: At normal pressure.
◉ Which part of the kingpin should the locking jaws close around?
Answer: The shank.
◉ When you get ready to back under the semi-trailer you should line
up: Answer: Directly in front of the trailer.
◉ How should you test the tractor semi-trailer connection for
security? Answer: Pull gently forward in low gear against the locked
trailer brakes, then look at it carefully.
◉ When should you use the hand valve to park a combination
vehicle? Answer: Never.
◉ You supply air to the trailer tanks by: Answer: Pushing in the
trailer air supply valve.
, ◉ Why should you be sure that the fifth wheel plate is greased as
required? Answer: 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: Answer:
Applying and releasing the trailer brakes and listening for brake
sounds.
◉ There are two things that a driver can do to prevent a rollover.
They are: (1) Keep the cargo as close to the ground as possible; and
(2): Answer: Go slowly around turns.
◉ Before you back under a trailer, make sure the: Answer: Trailer
brakes are locked.
◉ 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? Answer: Nothing is likely to happen until
you try to apply the brakes.
◉ The air leakage rate for a combination vehicle (engine off, brakes
on) should not be more than ___ PSI per minute. Answer: 4
◉ In normal driving, some drivers use the hand valve before
applying the brake pedal to prevent a jackknife. Which of these
EXAM 2026 QUESTIONS AND ANSWERS
SOLVED 100% CORRECT
◉ You should not back a tractor under a trailer until the whole air
system is: Answer: At normal pressure.
◉ Which part of the kingpin should the locking jaws close around?
Answer: The shank.
◉ When you get ready to back under the semi-trailer you should line
up: Answer: Directly in front of the trailer.
◉ How should you test the tractor semi-trailer connection for
security? Answer: Pull gently forward in low gear against the locked
trailer brakes, then look at it carefully.
◉ When should you use the hand valve to park a combination
vehicle? Answer: Never.
◉ You supply air to the trailer tanks by: Answer: Pushing in the
trailer air supply valve.
, ◉ Why should you be sure that the fifth wheel plate is greased as
required? Answer: 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: Answer:
Applying and releasing the trailer brakes and listening for brake
sounds.
◉ There are two things that a driver can do to prevent a rollover.
They are: (1) Keep the cargo as close to the ground as possible; and
(2): Answer: Go slowly around turns.
◉ Before you back under a trailer, make sure the: Answer: Trailer
brakes are locked.
◉ 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? Answer: Nothing is likely to happen until
you try to apply the brakes.
◉ The air leakage rate for a combination vehicle (engine off, brakes
on) should not be more than ___ PSI per minute. Answer: 4
◉ In normal driving, some drivers use the hand valve before
applying the brake pedal to prevent a jackknife. Which of these
