BCDL COMBINATION VEHICLES
QUESTIONS WITH COMPLETE
SOLUTION
How should you test the tractor semi trailer combination for being properly coupled? - Pull gently
forward in low gear against the locked trailer brakes, then inspect your coupling.
When coupling to the trailer, how far do you back up before stopping the first time? - Until the fifth
wheel plate just touches the trailer.
What do you check before backing under the trailer? - Make sure the trailer brakes are set.
Air lines on a combination vehicle are often colored to keep them from getting mixed up. What color is
the emergency line and what color is the service line? - Red and blue.
After you back up to the trailer and the fifth wheel plate touches the trailer, you set the tractor park
brake, get out and hook up the emergency and service air lines. Then what do you do before backing
under the trailer? - Supply air to the trailer system, then pull out the trailer air supply knob to fully set
the trailer brakes.
What three things can you do to prevent rollovers? - Keep your load centered, keep the load as low in
the trailer as possible, and go slow around turns.
How far do you raise the landing gear on your trailer? - Crank it up as far as it will go.
You have coupled with a semi trailer. In what position should you put the landing gear before driving
away? - Fully raised with the crank handle secured in its bracket.
When uncoupling, what could happen if you park the trailer at an angle? - You could do damage to the
landing gear and dolly legs.
Why should you lock the tractor glad hands together or couple them to the dummy glad hands when
bobtailing? - It will keep dirt and water out of the lines.
When backing under a trailer, you should expect the trailer to be lifted slightly by the fifth wheel plate. -
True.
Before you begin coupling, you should check your travel path for obstacles and hazards. - True.
What should your air supply pressure gauge read before backing under a trailer? - 100 - 125 psi.
In case of a jackknife situation, you can use your trailer hand valve to apply trailer brakes to stop the
trailer from skidding. - False.
QUESTIONS WITH COMPLETE
SOLUTION
How should you test the tractor semi trailer combination for being properly coupled? - Pull gently
forward in low gear against the locked trailer brakes, then inspect your coupling.
When coupling to the trailer, how far do you back up before stopping the first time? - Until the fifth
wheel plate just touches the trailer.
What do you check before backing under the trailer? - Make sure the trailer brakes are set.
Air lines on a combination vehicle are often colored to keep them from getting mixed up. What color is
the emergency line and what color is the service line? - Red and blue.
After you back up to the trailer and the fifth wheel plate touches the trailer, you set the tractor park
brake, get out and hook up the emergency and service air lines. Then what do you do before backing
under the trailer? - Supply air to the trailer system, then pull out the trailer air supply knob to fully set
the trailer brakes.
What three things can you do to prevent rollovers? - Keep your load centered, keep the load as low in
the trailer as possible, and go slow around turns.
How far do you raise the landing gear on your trailer? - Crank it up as far as it will go.
You have coupled with a semi trailer. In what position should you put the landing gear before driving
away? - Fully raised with the crank handle secured in its bracket.
When uncoupling, what could happen if you park the trailer at an angle? - You could do damage to the
landing gear and dolly legs.
Why should you lock the tractor glad hands together or couple them to the dummy glad hands when
bobtailing? - It will keep dirt and water out of the lines.
When backing under a trailer, you should expect the trailer to be lifted slightly by the fifth wheel plate. -
True.
Before you begin coupling, you should check your travel path for obstacles and hazards. - True.
What should your air supply pressure gauge read before backing under a trailer? - 100 - 125 psi.
In case of a jackknife situation, you can use your trailer hand valve to apply trailer brakes to stop the
trailer from skidding. - False.
