CDL COMBINATION VEHICLE STUDY GUIDE QUESTIONS
AND SOLUTIONS RATED A+
✔✔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
A. Controls the tractor air supply
B. Controls the air supply to the protection valve
C. Supplies the trailer with air
D. Supplies air to the tractor - ✔✔C. Supplies the trailer with air
✔✔The service air supply to the tractor tractor
, A. Controls the tractor airbrakes
B. Controls the air supply
C. Carries air to the trailer brakes
D. Carries air to the tractor brakes - ✔✔C. Carries air to the trailer brakes
✔✔How do you supply air to the trailer tanks
A. By pushing in the trailer air supply valve
B. By pulling out the trailer air supply valve
C by connecting the service line glad hand
D. By applying the trailer hand valve - ✔✔A. By pushing in the trailer air supply valve
✔✔In coupling, where should the tractor be lined up
A. In front of the king pin
B. Slightly to the right of the trailer
C. You should line up directly in front of the trailer
D. Slightly to the left of the trailer. - ✔✔C. You should line up directly in front of the
trailer
✔✔What should you do just before the tractor is coupled
A. Make sure that the tractor and trailer line up
B. Chalk the trailer wheels
C. Connect the emergency and service airlines
D. None of the above - ✔✔C. Connect the emergency and service airlines
✔✔The fifth wheel locking lever is not locked after the jaws close around the king pin.
What does this mean?
A. It means the trailer will not swivel on the fifth wheel
B. It means you cannot set the fifth wheel for weight balance
C. It means the parking lot is off and you may drive away
D. It means the coupling is not right and should be fixed before driving the coupled unit -
✔✔D. It means the coupling is not right and should be fixed prior to driving
✔✔To make sure that the king pin and fifth wheel connection are secure, what should
you do?
A. Slowly drive forward with the trailer brakes locked (tug test)
B. Get out of the vehicle look at fifth wheel king pin lock , safety latch is locked
C. Perform a tug test, after airlines are hooked up, using the hand valve ( trolley break)
D. All of the above - ✔✔D. All of the above
✔✔How much space should be between the upper and lower fifth wheel after coupling
A. At least 1/2 inch
B. About 3/4 inch
C. Just enough to see light through it
D. No space at all - ✔✔D. No space at all
AND SOLUTIONS RATED A+
✔✔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
A. Controls the tractor air supply
B. Controls the air supply to the protection valve
C. Supplies the trailer with air
D. Supplies air to the tractor - ✔✔C. Supplies the trailer with air
✔✔The service air supply to the tractor tractor
, A. Controls the tractor airbrakes
B. Controls the air supply
C. Carries air to the trailer brakes
D. Carries air to the tractor brakes - ✔✔C. Carries air to the trailer brakes
✔✔How do you supply air to the trailer tanks
A. By pushing in the trailer air supply valve
B. By pulling out the trailer air supply valve
C by connecting the service line glad hand
D. By applying the trailer hand valve - ✔✔A. By pushing in the trailer air supply valve
✔✔In coupling, where should the tractor be lined up
A. In front of the king pin
B. Slightly to the right of the trailer
C. You should line up directly in front of the trailer
D. Slightly to the left of the trailer. - ✔✔C. You should line up directly in front of the
trailer
✔✔What should you do just before the tractor is coupled
A. Make sure that the tractor and trailer line up
B. Chalk the trailer wheels
C. Connect the emergency and service airlines
D. None of the above - ✔✔C. Connect the emergency and service airlines
✔✔The fifth wheel locking lever is not locked after the jaws close around the king pin.
What does this mean?
A. It means the trailer will not swivel on the fifth wheel
B. It means you cannot set the fifth wheel for weight balance
C. It means the parking lot is off and you may drive away
D. It means the coupling is not right and should be fixed before driving the coupled unit -
✔✔D. It means the coupling is not right and should be fixed prior to driving
✔✔To make sure that the king pin and fifth wheel connection are secure, what should
you do?
A. Slowly drive forward with the trailer brakes locked (tug test)
B. Get out of the vehicle look at fifth wheel king pin lock , safety latch is locked
C. Perform a tug test, after airlines are hooked up, using the hand valve ( trolley break)
D. All of the above - ✔✔D. All of the above
✔✔How much space should be between the upper and lower fifth wheel after coupling
A. At least 1/2 inch
B. About 3/4 inch
C. Just enough to see light through it
D. No space at all - ✔✔D. No space at all
