combination

Question 1

You should not back a tractor under a trailer until the whole air system is

Answer 1

At normal pressure

Question 2

You are coupling a semi trailer to your tractor but have not yet backed under. The trailer is at the right height when

Answer 2

It will be raised slightly when the tractor is backed under it

Question 3

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

Answer 3

The shank

Question 4

When you get ready to back under the semi trailer you should line up

Answer 4

Directly in front of the trailer

Question 5

How should you test the tractor semi trailer connection for security?

Answer 5

Pull gently forward in low gear against the locked trailer brakes, then look at it carefully

Question 6

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

Answer 6

Never

Question 7

You supply air to the trailer tanks by

Answer 7

Pushing in the trailer air supply valve

Question 8

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

Answer 8

To prevent steering problems

Question 9

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

Answer 9

Applying and releasing the trailer brakes and listening for brake sounds

Question 10

There are two things that a driver can do to prevent a roll over. They are: (1) Keep the cargo as close to the ground as possible; and (2)

Answer 10

Go slowly around turns

Question 11

Before you back under a trailer, make sure the

Answer 11

Trailer brakes are locked

Question 12

If the service air line comes apart while you are driving a combination vehicle but the emergency line stays together, what will happen right away?

Answer 12

Nothing is likely to happen until you try to apply the brakes

Question 13

The air leakage rate for a combination vehicle (engine off, brakes on) should not Be more than ____ psi per minute

Answer 13

4

Question 14

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

Answer 14

It should not be done.

Question 15

The driver crosses the air lines when hooking up to an old trailer. What will happen?

Answer 15

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

Question 16

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

Answer 16

It will keep dirt and water out of the lines

Question 17

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

Answer 17

Over the locking lever

Question 18

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

Answer 18

a. There is enough clearance between the tractor frame and the landing gear.
b. There is enough clearance between the tops of the tractor tires and the nose of the trailer.

Question 19

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

Answer 19

Trailer emergency brakes to come on

Question 20

When backing under a tractor under a trailer you should expect

Answer 20

Trailer will be lifted slightly when the tractor backs under it

Question 21

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

Answer 21

The emergency and service air lines

Question 22

You have coupled with a semi trailer. In what position should you put the front trailer supports before driving away?

Answer 22

Fully raised with the crank handle secured in its bracket

Question 23

Air lines on a combination vehicle are often colored to keep them from getting mixed up. The emergency line is ____; the service line is ____.

Answer 23

Red, blue

Question 24

Which of these statements is true?

Answer 24

“bobtail” tractors can take longer to stop than a combination vehicle loaded to the maximum gross weight

Question 25

You are coupling a tractor and semi trailer and have connected the air lines. Before backing under the trailer, you should

Answer 25

Supply air to the trailer system, then pull out the air supply knob to lock the trailer brakes

Question 26

The hand valve should be used

Answer 26

To test the trailer brakes

Question 27

The air leakage rate for a combination vehicle (engine off, brakes off) should be no more than ____ psi per minute

Answer 27

3

Question 28

The fifth wheel locking lever is not locked after the jaws close around the kingpin. This means tha

Answer 28

The coupling is not right and should be fixed before driving the vehicle

Question 29

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

Answer 29

The tractor protection valve to close

Question 30

Semi trailers made before 1975 that are equipped with air brakes

Answer 30

Often do not have spring brakes