CDL Combination
Vehicles Test

Select the load of the trailer that will require the shorter distance to stop.

Make sure that_____before you back under a trailer.

How do you check the connection after locking the kingpin into the fifth wheel?

Select the false statement about tractor protection valves.

The front trailer supports should be____before driving away.

Make sure____when the front trailer supports are up and the trailer is sitting on the tractor.

Select the statement that best explains the "crack-the-whip" effect.

It is good practice to_____when uncoupling.

What should you hook up before backing a tractor to a trailer for coupling?

What might happen if a trailer is too high when you try to couple?

A trailer is at the right height to have the tractor backed up to it when:

Select the true statement in regards to what the fifth wheel should be checked for.

How do you make sure the air lines are not crossed and the trailer brakes are working after supplying air to the trailer?

Off-tracking happens when going around a corner and:

You must first______to supply air to the trailer.

Select the answer that is controlled by the foot brake.

You should expect____when backing a tractor under a trailer.

Select the step that comes first:

Select the two things that are important in preventing a rollover:

To prevent a roll over a driver can 1) keep the cargo as low to the ground as possible and 2) _____.

The safety catch for the fifth wheel locking lever must be ____ for a coupling to be complete.

The emergency air line is _____and the service air line is____.

What should you do before you begin to couple?

You need to raise the landing gear just to the height of where it clears the pavement before driving.

What position should the tractor protection control valve be in after coupling?

The _____of the kingpin has the locking jaw close around it.

Select the definition of "off-tracking."

Select the situation in which you should use the hand valve to park a combination vehicle.

Before backing under the trailer you should______when coupling a tractor and trailer with air lines already connected.

The air leakage rate for combination vehicles should not be more than _ psi a minute.

When you have a major leak in the service line and you apply pressure to the brakes, the service air pressure will escape and:

A tractor should not be backed under a trailer until the whole air system is:

How high should you crank the landing gear?

Select the true statement in regards to large combination vehicles taking longer to stop.

The locking jaws of the kingpin should close around:

Select the vehicle that off-tracks the most.

If you park the trailer at an angle to the tractor when uncoupling:

Select the statement that describes how you could damage the landing gear.

What will happen should a driver cross the air lines when hooking up the an older trailer?

The trailer should be lowered so that _____.