CDL Combination
Vehicles Test

You should have the fifth wheel plate greased as recommened because:

When driving a combination vehicle, the trailer breaks away severing the air lines. The trailer brakes should come on and ____.

Before backing under the trailer after connecting the air lines you should:

You must first______to supply air to the trailer.

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

Select the false statement about tractor protection valves.

Which trailer is most likely to turn over when you make a sudden turn while pulling doubles?

Check to ensure that____when inspecting the coupling.

What is the earliest way to notice a trailer skid?

How should the hand valve be used?

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

The trailer should be lowered so that _____.

What will occur if you cross the connect the air lines?

The front trailer supports should be____before driving away.

The purpose for the emergency air line is:

What should you do if you start a trailer skid?

To test the tractor-trailer connection for security, you should:

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

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

Select the vehicle that off-tracks the most.

Select the step that comes first:

What is the service air line controlled by?

The emergency air line is used to:

Select the reason as to why you should not use the trailer hand valve while driving.

The cause of almost half of all truck driver deaths are:

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

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

You should make sure the_____before backing under a trailer.

Why should you use chocks when parking a trailer without spring brakes?

The locking jaws of the kingpin should close around:

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

Select the statement that best describes what the trailer air supply control does:

Select the portion of the combination vehicle that is most likely to turn over suddenly when pulling a double trailer:

When you have a major leak in the service line and put on the brake, the service air pressure will escape and cause the:

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

How do you supply air to the trailer tanks?

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

Where should the safety catch for the fifth wheel locking lever be located for coupling to be complete?

Select the true statement:

Select what you should not do when coupling the glad hands.