Prevents air from escaping an air brake system.

Is located on the front of a trailer.

Is located on the instrument panel.

Are more likely to roll over than empty rigs.

Are less likely to roll over than empty rigs.

Are just as likely to roll over as empty rigs.

Kansas CDL Combination 2 - DMV Written Test Questions with Answers

Q.1

When driving a tractor-trailer equipped with ABS, you should:

Stop harder than you would otherwise.
Use extra braking force to ensure the ABS kicks in.
Brake as you normally would.
Brake using less pressure than you would otherwise use.

Q.2

When glad hands are coupled, the seals should be pressed together at an angle of:

30 degrees.
45 degrees.
60 degrees.
90 degrees.

Q.3

Before backing your tractor under the trailer, make sure your trailer brakes are:

Disengaged.
Locked.
Deactivated.
Dry.

Q.4

If oil and water build up in your vehicle's air tanks, the brakes:

May not work correctly.
May feel squishy.
Will squeal loudly when used.
Will be extremely sensitive.

Q.5

Trailers with low underneath clearance may be difficult to drive:

On interstate highways.
Over railroad crossings.
On dirt roads.
At the posted speed limit.

Q.6

After coupling, there should be ____ between the upper and lower fifth wheel.

No space
Very little space
A lot of space
Three inches of space

Q.7

If you need to back your trailer but cannot back up in a straight path, you should:

Back toward the passenger's side.
Back toward the driver's side.
Swerve back and forth while backing.
Always turn to your right.

Q.8

After finishing a pre-trip inspection, you should:

Close the service line valve.
Remove the service line valve.
Leave the emergency line valve open.
Leave the rear shut-off valves open.

Q.9

While inspecting a coupling, you should go under the trailer and:

Detach the jaws from around the kingpin.
Make sure the locking lever is in the "emergency" position.
Remove the safety latch.
Look into the back of the fifth wheel.

Q.10

A tractor protection valve is:

A device that keeps air in the tractor or truck brake system, should the trailer break away or develop a bad leak.
A device that prevents theft.
A device that controls fuel levels.
A device that allows the battery to recharge efficiently.

Q.11

If a trailer begins to skid, the driver should:

Lock the brakes.
Release the brakes.
Steer in the opposite direction.
Accelerate.

Q.12

Simply changing lanes can cause:

A “crack-the-whip” effect, resulting in a rollover.
A trailer to straighten out.
Confusion over which lane the driver is hoping to use.
Other drivers to reduce their speed.

Q.13

What happens when the wheels of a trailer lock up?

The trailer will usually continue to move in a straight line.
The trailer will disengage.
The trailer will likely swing around.
The trailer will stop.

Q.14

What is a tractor protection valve?

A valve to keep air in the brake system should there be a bad leak
A valve that prevents the truck from being stolen
A valve that prevents the driver from going too fast
A valve that prevents the trailer from accidentally being released

Q.15

A shut-off valve:

Is located on the front of a trailer.
Is located on the instrument panel.
Prevents air from escaping an air brake system.
Should always be open.

Q.16

Air pressure in the ____ air line is controlled by either the foot brake or trailer hand brake.

Emergency
Service
Rear
Auxiliary

Q.17

Fully-loaded rigs:

Are less likely to roll over than empty rigs.
Are more likely to roll over than empty rigs.
Are just as likely to roll over as empty rigs.
Should not be driven.

Q.18

Pull out the trailer air supply control to test:

The parking brake.
The trailer emergency brakes.
The trailer service brakes.
The landing gear.

Q.19

To prevent a rollover, a driver should:

Keep cargo low.
Place cargo high.
Keep cargo loose.
Turn quickly.

Q.20

The service air line is attached to the:

Relay valves.
Supply line.
Emergency air line.
Steering wheel.