CDL Combination
Vehicles Test

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

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

What will happen right away should the service air line come apart but the emergency line is intact while driving a combination vehicle?

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

Where are shut-off valves located?

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

Select the vehicle that off-tracks the most.

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

The air leakage rate for a combination vehicle should not exceed ____psi a minute.

Select the true statement in regards to as why you should make sure the fifth wheel plate is greased as recommended:

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

Off-tracking happens when going around a corner and:

What is the earliest way to notice a trailer skid?

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

Select the true statement:

How should the hand valve be used?

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

It is good practice to_____when uncoupling.

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

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

You should back up slowly until____when coupling the trailer.

You should make sure the_____before backing under a trailer.

Select the step that comes first:

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

Select the true statement:

What should you do if you start a trailer skid?

What is the service air line controlled by?

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

Select the answer that is controlled by the foot brake.

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

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

How do you supply air to the trailer tanks?

When not towing a trailer, why should the tractor glad hands be locked?

How should the trailer be lined up when preparing to back the tractor up?

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

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

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

Remember to_____to prevent rollovers.

The emergency air line is used to:

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