CDL Combination Vehicles Test | Free Practice Questions

Combination Vehicles Test #1
(english)

Combination Vehicles Test #1 (en)

1 / 20

Where should the tractor be when you uncouple the trailer and inspect the landing gear?

With the tractor frame under the trailer.

Next to the trailer, but not aligned with it.

Parked at a 45-degree angle to the trailer

2 / 20

There are two ways a driver can stop a truck from rolling over. They are: (1) put the load as low as possible and (2):

Go slow around turns.

Drive with windows open.

Keep both hands firmly on the steering wheel.

3 / 20

When testing a combination vehicle, with the engine turned off and the brakes applied, the air shouldn't leak out faster than ______ psi every minute.

4 / 20

lf you are not pulling a trailer, why should you lock the tractor glad hands together (or use dummy couplers)?

It helps balance the air pressure between the tractor and trailer.

To make it easier to attach to a trailer later.

It will keep dirt or water out of the lines.

5 / 20

How can you stop a trailer from skidding?

Apply the brakes

Release the brakes.

Tap the brakes lightly.

6 / 20

For a combination vehicle that uses air brakes, when the engine is off and the brakes are off, the air brake leakage rate should not be more than ___ psi every minute.

1/2

7 / 20

What is the proper position for the fifth wheel when coupling with a trailer?

Slanted sideways towards the driver's side

Above the roof of the truck

Tilted down toward the end of the trailer.

8 / 20

What is correct out of the following?

Brakes work more effectively when the vehicle is empty.

Braking efficiency increases as vehicle weight decreases.

Bobtail tractors can take longer to stop than a combination vehicle loaded to maximum gross weight.

9 / 20

A tractor pulling a____ trailer needs the longest distance to stop.

Heavily modified

Empty

Slightly damaged

10 / 20

For a coupling to be properly done, the safety latch on the fifth wheel locking lever must be ___.

Over the locking lever

Beside the locking lever

In front of the locking lever.

11 / 20

When operating a combination vehicle, the trailer unexpectedly disconnects, causing both air lines to separate. In addition to the trailer brakes coming on, you expect:

The trailer lights to go out.

The tractor protection valve to close.

The emergency brakes to release.

12 / 20

When you're driving behind another car in good weather, make sure there's at least one second of space for every ____ feet of your vehicle's length.

13 / 20

Youre getting ready to reverse your tractor under a semitrailer. The semitrailer is at the correct height when the:

Kingpin locks into place without any adjustment needed.

Fifth wheel is completely visible below the trailer.

Trailer will be lifted slightly when the tractor backs under it.

14 / 20

Trailers with air brakes made before 1975:

Usually need a glad hand converter.

Are not required to have spring brakes.

Cannot be legally operated on interstate highways.

15 / 20

Why is it necessary to put grease on the fifth wheel plate?

To improve fuel efficiency.

To prevent steering problems.

To enhance tire traction.

16 / 20

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

Less control over the brakes

Harder to accelerate.

Easier to turn over.

17 / 20

After you hook up the air lines, but before you back up under the trailer, you should:

Disconnect the electrical line.

Check the tire pressure on the trailer.

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

18 / 20

When uncoupling the trailer, after you turn off the trailer air supply and make sure the trailer's brakes are set, you should:

Check the engine oil level.

Back up gently to ease pressure on the fifth wheel.

Check the trailer's tire pressure.

19 / 20

After coupling the trailer with the tractor, in what position should the tractor protection control valve be set?

Left position

Normal position

Horizontal position

20 / 20

When driving a truck with two trailers, which shut-off valve do you have to close on the last trailer?

Back valve.

Side valve

Front valve.

Your score is

The average score is 60%

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Combination Vehicles Test #2 (english)

What is the CDL Air Brakes Test?

The CDL Combination Vehicles test is a written exam that evaluates your knowledge of safely operating combination vehicles. It covers topics specific to these types of vehicles, including:

Coupling and uncoupling trailers
Handling characteristics of combination vehicles
Inspecting combination vehicles
Safe operating practices

Who Needs to Take the CDL Combination Vehicles Test?

Anyone wanting to drive a combination vehicle needs to pass this test. This includes drivers of:

Tractor-trailers
Truck and trailer combinations
Other vehicles with a GVWR of 26,001 pounds or more, towing a trailer over 10,000 pounds

Why are Practice Tests Important?

Practicing for the CDL Combination Vehicles test is vital for success. Here’s why:

Familiarization: Practice tests get you used to the real exam’s format, question types, and time limits.
Knowledge Assessment: They help you gauge your current understanding and pinpoint areas needing more study.
Confidence Building: Seeing your progress on practice tests boosts your confidence and reduces test anxiety.
Improved Performance: Studies show that those who use practice tests do significantly better on exams.