Combination (Class A) Vehicle Test 3

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

Directly in front of the trailer

To stop a trailer skid, you should:

Release the service brakes

The air leakage rate for a combination of two vehicles (engine off, brake off) should not be greater than __ psi per minute.

3

Before you back under a truck trailer, make sure the:

Trailer brakes are locked

There are two things that a driver can do to prevent a rollover. They are: (1) Go slow around turns: and (2):

Keep the cargo as close to the ground as possible

After the trailer has been coupled to the tractor, the tractor protection control valve should be placed in the __ position.

Normal

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

The tractor ahead gently with the trailer brakes locked

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

Back up gently to ease pressure on the fifth wheel locking jaws

If you cannot make a turn without entering another traffic lane, you should:

Turn wide as you complete your turn

Loss of air pressure in the emergency line causes:

The trailer’s emergency brakes to come on

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

It should not be done

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

Emergency

You have a major leak in the service line and you put on the brakes. Service air pressure will escape and cause the:

Trailer emergency brakes to come on

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

If the trailer has no spring brakes, you could drive away, but you will not have trailer brakes

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

At normal pressure