CDL Combination Test Questions and Answers 2023

CDL Combination Test Questions and Answers 2023: Our CDL combination vehicles practice test will help you to pass the tests for combination vehicles Endorsements written test (tractor-trailer, doubles, triples, straight truck and trailer). The Combination Test Questions and Answers is only to give you the minimum knowledge needed for a written test of combination vehicles.

Combination vehicles are usually heavier, longer, and require more driving skills than single commercial vehicles. This means that drivers of combination vehicles need more knowledge and skill than drivers of single vehicles. In this chapter, we talk about some important safety factors that apply specifically to combination vehicles.

CDL Combination Test Questions and Answers 2023

CDL Combination Test Questions and Answers

Test Name CDL Practice Test 2023
Language English
License Endorsements Permit
Total Questions 30 sample questions
Test For Commercial Driver License
Test Preparation Combination vehicles Endorsements
Country USA
Explanation No
0 votes, 0 avg

CDL Combination Vehicles Test

1 / 30

The standard following distance behind other vehicles is at least

2 / 30

Which of the following is a coupling device used to connect the service and emergency air lines from the truck or tractor to the trailer?

3 / 30

When parking trailers without spring brakes, use _________ to safely secure the vehicle.

4 / 30

Fully loaded rigs are __________ times more likely to rollover in a crash than empty rigs

5 / 30

You are coupling a tractor and semitrailer, and ready to back your trailer under a semi-trailer. When is the trailer at the right height?

6 / 30

Failure to keep the _________ lubricated could cause steering problems because of friction between tractor and trailer.

7 / 30

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

8 / 30

The tractor protection valve will close automatically if air pressure is low or in the range of

9 / 30

The earliest and best way to recognize that your trailer has started to skid is by

10 / 30

After the tractor has coupled with the semitrailer, in what position should you put the front trailer supports, or landing gear, before driving away?

11 / 30

Emergency lines on combination vehicles are often color coded to keep them from getting mixed up. The service lines are coded with the color __________, and the emergency lines are coded with the color __________ .

12 / 30

In combination vehicles, the trailer service brake should be tested with the ________, but controlled in normal operation with the _________.

13 / 30

To supply air to the trailer air tanks in a combination vehicle, you must

14 / 30

Why should the trailer glad hands be locked together or attached to “dead end,” or dummy, couplers when not in use?

15 / 30

What will happen if the service air line comes apart while you are driving a combination vehicle?

16 / 30

When coupling a tractor and semitrailer, you must lock the kingpin into the fifth wheel. Which is the best way to check the connection?

17 / 30

When should the trailer hand valve be used?

18 / 30

The “normal” position of the trailer air supply control is used for

19 / 30

Which of the following may happen if the tractor protection valve doesn’t work right?

20 / 30

Which of the following reduces the risk of rollover?

21 / 30

Which of the following is the correct definition of offtracking?

22 / 30

Your trailer has begun to skid. You should

23 / 30

When lowering the landing gear of a loaded trailer,

24 / 30

When coupling, the fifth wheel jaws should close around the __________________ of the kingpin.

25 / 30

If the service and emergency air lines are crossed when hooking up an old trailer, what will happen?

26 / 30

When the wheels of a trailer lock up and the trailer begins to swing around ______ is likely to occur.

27 / 30

The air leakage rate for a combination vehicle (engine off, brake off) should be less than _________ psi per minute

28 / 30

When coupling with a semitrailer, back the tractor up

29 / 30

What are the two purposes of the emergency air line on combination vehicles?

30 / 30

When coupling a tractor to a semitrailer, what should you hook up before backing under the trailer?

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