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Free District of Columbia CDL Combination Vehicles Practice Test 2023

You have to pass the CDL combination vehicles endorsement to get ready for propelling your career with your license. You are looking for a good DC CDL practice test source for your coming CDL test? You are in the right place. Our practice test is a great resource for beginners. The CDL practice test is designed for you to have exactly the experience of the exam as you will be more familiar with both the test format and the subject. They cover topics ranging from combination vehicle maintenance to safely driving a complex rig. Each question is based on the official DC CDL Manual so you can be sure that the information in our test is accurate and relevant to your examination. In addition, each question has a detailed explanation so that it is very useful for you to learn from your mistakes. Preparing well before test day with questions and content that we cover. Start with our Free District of Columbia CDL Combination Vehicles Practice Test today and walk out with your endorsement!

Our CDL practice tests:
Based on 2021 DC commercial driver's license manual
Full answers + detailed explanations
Perfect for first-time, renewal applicants
DC CDL Combination Vehicles Test format:
20 questions
16 correct answers to pass
80% passing score
Study now
List of questions
1.
A tractor with a _______ trailer, requires the most amount of stopping distance.
2.
The trailer air supply control knob is:
3.
To prevent water and dirt from entering the air system, hose couplers can be attached to dummy couplers or:
4.
When uncoupling, make sure that the parking area:
5.
When connecting the glad hands, press the two seals with the couplers together at what degree to each other?
6.
After you lock the kingpin into the fifth wheel, you should check the connection by:
7.
To make coupling and uncoupling a loaded trailer easier:
8.
When you notice that your trailer has lost traction and is going into a skid, you should:
9.
How should you test the tractor-semitrailer connection for security?
10.
There are two things that a driver can do to prevent a rollover: They are: (1) go slow around turns, and (2):
11.
Why should you be sure that the fifth wheel plate is greased as required?
12.
A fifth wheel in proper position for coupling will have:
13.
To stop a trailer skid you should:
14.
You supply air to the trailer tanks by:
15.
Like tractor air tanks, trailer air tanks should be kept free of dirt and oil by:
16.
The "rearward amplification" value means _______.
17.
When coupling, the proper position of the fifth wheel is:
18.
When driving a set of doubles, it is necessary to close which shut-off valve in the last trailer:
19.
At the back of trailer used to tow other trailers are shut-off valves, also called:
20.
You are coupling a tractor to the semitrailer; you have connected the airlines. Before backing under the trailer, you should:
District-of-columbia Pre-Trip TestDistrict-of-columbia Hazmat TestDistrict-of-columbia School Bus TestDistrict-of-columbia Air Brake TestDistrict-of-columbia General Knowledge TestDistrict-of-columbia Combination Vehicles TestDistrict-of-columbia Doubles/ Triples Trailers TestDistrict-of-columbia Tanker Vehicles TestDistrict-of-columbia Passenger Vehicles Test