Permit Combination Vehicle Practice Test

When backing a tractor under a trailer, you should:

After the trailer has been coupled to the tractor, the tractor protection valve should be placed in what position?

The fifth wheel locking lever is not locked after the jaws have closed around the kingpin. This means that:

Off-tracking or cheating causes which of these to follow the wider pass while making a turn?

The air lines on combination vehicles are often colored to prevent them from getting mixed up. The emergency line is____and the service line is____:

Semi trailers made before 1975 that are equipped with air brakes:

The air leakage rate for a combination vehicle(engine off, brakes on) should be less than____psi per minute:

Compared to a straight truck or bus there are___things to inspect on comination vehicles:

A tractor with a ____ trailer will require the shortest amount of stopping distance:

When you get ready to back under a semitrailer, you should line up:

To unlock the fifth wheel, the locking lever should be placed in the ____ position:

The tractor protection valve will close and the trailer emergency brakes will come on when there is a major leak in the ____ brake line:

When coupling, the proper position of the fifth wheel is:

What gear should the tractor be in after you uncouple the trailer and are inspecting the                trailer supports?

You have coupled to a semitrailer. Where should you put the iron trailer supports before driving away?

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

After you supply air to the trailer, make sure the air lines are not crossed and the trailer brakes are working. This is done by:

Before you back under a trailer, make sure that:

When you are uncoupling a loaded trailer, you should lower the landing gear until it:

What will happen if the air lines are crossed when you hook up to an old trailer?

There are two things a driver can do to prevent a rollover. They are (1) keep the cargo as close to the ground as possible and (2):

To stop a trailer skid:

Why should you be sure the fifth wheel plate is greased as required?

Your emergency air line breaks or gets pulled apart while driving. The loss of pressure will cause the:

When connecting the glad hands, press the two coupler rubber seals together at what angle to each other?

Which of these statements is true?

After you have coupled the trailer, you should start raising the landing gear by using:

You supply air to the trailer tanks by:

Which part of the kingpin should the locking jaws close around?

How much space should be allowed between the upper and lower fifth wheel after coupling?

You have pushed in the trailer air supply valve. You should not back a tractor under a trailer until the whole system is:

You are coupling a tractor to a semitrailer. You have connected the air lines. Before backing under the trailer, you should:

The air brake leakage rate for a combination vehicle (engine off, brakes off) should be less than___psi per minute:

The safest way to make a turn without entering another traffic lane is to:

The higher the center of gravity of your truck, the:

The hand valve should be used:

When driving a set of doubles it is necessary to close which shut- off valves on the last trailer?

If the service line comes apart while driving a comb ination vehicle, but the emergency line stays together, what will happen right away?

You are coupling a tractor to a semitrailer and have backed up but are not under it. What should you hook up before backing under?

Why should you lock the tractor glad hands to each other or to a dummy coupler when you are not towing a trailer?

While driving behind another vehicle under good conditions you should allow at least one second  between your vehicle and the vehicle ahead for each____(how many) feet of your vehicle length?

Glad hands are usually connecting which of these:

You are about to back your tractor under a semitrailer. The trailer is at the right height when:

While checking if the trailer is securely coupled to the trailer, the landing gear should be:

Air and electrical lines from the tractor to the trailer should be:

After you lock the kingpin into the fifth wheel, you should check the connection by:

Where should the tractor be when you inspect the landing gear after uncoupling from the trailer?

The front trailer supports are up and the trailer is resting on the tractor. Make sure

When uncoupling the trailer, after you shut off the trailer air supply and lock the trailer brakes, you should:

Air brake equipped trailers made before 1975:

When checking the trailer emergency brakes the tractor protection valve should be placed in what position?

You are driving a combination vehicle when the trailer breaks away, pulling apart both air lines.  You expect the trailer emergency brakes to come on and:

In normal driving, some drivers use the hand valve before the brake pedal to prevent a jackknife. Which of these statements is true?

When should you use the hand valve to park a combination vehicle?