CDL COMBINATION VEHICLE CORE EXAMS TEST
QUESTIONS AND SOLUTIONS RATED A+
✔✔You have coupled with a semi trailer, where should you put the front trailer supports
before driving away?
A. Raised halfway with the crank handle secured.
B. Raised 3/4 of the way with the crank handle secured
C. Fully raised with the crank handle secured
D. Three turns off the top with the crank handle secured - ✔✔C. Fully raised with the
crank handle secured
✔✔Why should you not use the hand valve, trolley break, to park a combination
vehicle?
A. It's not a parking brake
B. To hold the truck in from rolling at an intersection
C. To hold the vehicle from rolling back on a grade
D. All of the above - ✔✔D. All of the above
✔✔The front trailer supports are up and the trailer is resting on the tractor. Make sure
there is
A. Enough clearance between the tractor frame and the landing gear
B. Enough clearance between the tops of the tractor tires and the nose of the trailer
C. Both a and B are correct
D. Neither a or B are correct - ✔✔C. Both a and B are correct
✔✔There are two things a driver can do to prevent a rollover, keep the weight as close
to the ground as possible and—
A. Make sure the brakes are properly adjusted
B. Keep both hands firmly on the steering wheel
C. Go slow around turns
D. Make sure you're traveling at the posted speed limit - ✔✔C. Go slow around curves
✔✔In normal driving some drivers use the hand valve (trolley brake) before the brake
pedal to prevent a jack knife, which of these statements is true?
A. It should not be done
B. It results in less skidding when using the brake pedal alone
C. It lets the driver steer with both hands
D. It is the best way to brake keep keep the truck in a straight line - ✔✔A. It should not
be done
✔✔When should you use the hand valve ( trolley break) to park a combination vehicle
A. To park at loading dock
B. To park for less than two hours
C. To park on a grade.
, D. Never - ✔✔D. Never
✔✔A device which allows the trailer brakes to be applied more quickly then would
otherwise be possible.
A. Quick release valve
B. Relay valve
C. Front wheel limiting valve
D. S-Cam - ✔✔B. Relay valve
✔✔Off tracking is,
A, When the rear wheel follows a different path than the front wheels
B. The process of taking the track off a tractor
C. When a driver fails to keep the wheel on track
D. An error in keeping track of the hours and miles driven - ✔✔A. When the rear wheels
follow a different path than the front wheels
✔✔Airbrake equipped trailers made before 1975
A. Often do not have spring breaks
B. Are easier to break the newer trailers because they are heavier
C. Usually need a glad hand converter
D. Cannot be legally operated on interstate highways - ✔✔A. Often do not have spring
brakes
✔✔Why should you be sure that the fifth wheel has a enough grease?
A. To prevent steering problems
B. To keep the break in place
C. To reduce heat and noise
D. To ensure that the bearings inside do not burn up - ✔✔A. To prevent steering
problems
✔✔You are coupling a tractor to a trailer and have backed up but are not under it. What
should you hook up before backing under the trailer?
A. The electrical service cable
B. The emergency service lines
C. Nothing, back up and lock the fifth wheel. - ✔✔B. The emergency and service lines
✔✔You need—— —Times more stopping distance when stopping a combination at 40
mph then at 20 mph.
A. Three times
B. Four times
C. Eight times
D. 10 times - ✔✔B. Four times
✔✔The trailer air supply
QUESTIONS AND SOLUTIONS RATED A+
✔✔You have coupled with a semi trailer, where should you put the front trailer supports
before driving away?
A. Raised halfway with the crank handle secured.
B. Raised 3/4 of the way with the crank handle secured
C. Fully raised with the crank handle secured
D. Three turns off the top with the crank handle secured - ✔✔C. Fully raised with the
crank handle secured
✔✔Why should you not use the hand valve, trolley break, to park a combination
vehicle?
A. It's not a parking brake
B. To hold the truck in from rolling at an intersection
C. To hold the vehicle from rolling back on a grade
D. All of the above - ✔✔D. All of the above
✔✔The front trailer supports are up and the trailer is resting on the tractor. Make sure
there is
A. Enough clearance between the tractor frame and the landing gear
B. Enough clearance between the tops of the tractor tires and the nose of the trailer
C. Both a and B are correct
D. Neither a or B are correct - ✔✔C. Both a and B are correct
✔✔There are two things a driver can do to prevent a rollover, keep the weight as close
to the ground as possible and—
A. Make sure the brakes are properly adjusted
B. Keep both hands firmly on the steering wheel
C. Go slow around turns
D. Make sure you're traveling at the posted speed limit - ✔✔C. Go slow around curves
✔✔In normal driving some drivers use the hand valve (trolley brake) before the brake
pedal to prevent a jack knife, which of these statements is true?
A. It should not be done
B. It results in less skidding when using the brake pedal alone
C. It lets the driver steer with both hands
D. It is the best way to brake keep keep the truck in a straight line - ✔✔A. It should not
be done
✔✔When should you use the hand valve ( trolley break) to park a combination vehicle
A. To park at loading dock
B. To park for less than two hours
C. To park on a grade.
, D. Never - ✔✔D. Never
✔✔A device which allows the trailer brakes to be applied more quickly then would
otherwise be possible.
A. Quick release valve
B. Relay valve
C. Front wheel limiting valve
D. S-Cam - ✔✔B. Relay valve
✔✔Off tracking is,
A, When the rear wheel follows a different path than the front wheels
B. The process of taking the track off a tractor
C. When a driver fails to keep the wheel on track
D. An error in keeping track of the hours and miles driven - ✔✔A. When the rear wheels
follow a different path than the front wheels
✔✔Airbrake equipped trailers made before 1975
A. Often do not have spring breaks
B. Are easier to break the newer trailers because they are heavier
C. Usually need a glad hand converter
D. Cannot be legally operated on interstate highways - ✔✔A. Often do not have spring
brakes
✔✔Why should you be sure that the fifth wheel has a enough grease?
A. To prevent steering problems
B. To keep the break in place
C. To reduce heat and noise
D. To ensure that the bearings inside do not burn up - ✔✔A. To prevent steering
problems
✔✔You are coupling a tractor to a trailer and have backed up but are not under it. What
should you hook up before backing under the trailer?
A. The electrical service cable
B. The emergency service lines
C. Nothing, back up and lock the fifth wheel. - ✔✔B. The emergency and service lines
✔✔You need—— —Times more stopping distance when stopping a combination at 40
mph then at 20 mph.
A. Three times
B. Four times
C. Eight times
D. 10 times - ✔✔B. Four times
✔✔The trailer air supply
