Combinations

Question 1

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

Answer 1

With the tractor frame under the trailger

Question 2

While driving behind another vehicle, under good conditions, you should allow at least one second between your vehicle and the vehicle ahead for each ____ feet of your vehicle length

Answer 2

10 ft

Question 3

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

Answer 3

Go slow around turns

Question 4

The air brake leakage rate for a combination vehicle ( engine off, brakes off) should not be more than ___ psi

Answer 4

3

Question 5

If you cannot complete your turn without entering another traffic lane you should

Answer 5

Turn wide as you complete the turn

Question 6

The higher the center of gravity of your truck, the

Answer 6

Easier to turn over

Question 7

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

Answer 7

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

Question 8

Glad hands are usually connecting which of these

Answer 8

service and emergency air lines from the vehicle to the trailer

Question 9

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

Answer 9

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

Question 10

The hand valve should be used

Answer 10

To test the trailer brakes

Question 11

When driving a set of doubles, it is necessary to close which shut-off valve in the last trailer

Answer 11

back valve

Question 12

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

Answer 12

Trailer will be lifted slightly when the tractor backs under it

Question 13

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

Answer 13

Emergency trailer brakes to come on

Question 14

If the spring brakes are not released when you pushed the trailer air supply valve you should

Answer 14

Check air line connection

Question 15

Air brake equipped trailers made before 1975

Answer 15

Are not required to have spring brakes

Question 16

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

Answer 16

Keep the cargo as close to the ground as possible

Question 17

After connecting the air lines but before backing under the trailer you should:

Answer 17

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

Question 18

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

Answer 18

The shank

Question 19

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

Answer 19

None

Question 20

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

Answer 20

At normal pressure