CDL Combination
Vehicles Test

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

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

Where are shut-off valves located?

What is the service air line controlled by?

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

Select the true statement:

The purpose for the emergency air line is:

Select the false statement about tractor protection valves.

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

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

There should be ___space between the upper and lower fifth wheel after coupling.

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

You should follow behind other vehicles ______when traveling under 40 mph.

Make sure that_____before you back under a 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:

After coupling with a trailer, what position should the front trailer supports be in before driving away?

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

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

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

To test the security of the tractor semi trailer connection you should:

When should the trailer hand valve be used?

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

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

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

Select the vehicle that off-tracks the most.

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

Check to ensure that____when inspecting the coupling.

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

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

What is the earliest way to notice a trailer skid?

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

Select the corect setup for shut-off valves:

When driving normally, some drivers use the hand valve before applying the brake pedal to prevent jack knifing. Select the most appropriate response to this statement.

Select the step that comes first:

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

Select why you should not use the trailer hand valve while driving:

Select the answer that is controlled by the foot brake.

You should back up slowly until____when coupling the trailer.