District of Columbia CDL Class A, B or C DMV Practice Tests & Cheat Sheets

CDL Class A, B or C. Complete CDL driver training course. All the questions in this test are from the official DMV written exam. You can use our free online tests to evaluate how likely you are to pass the official DMV test. Or you can just cut to the chase and increase your chances of passing by upgrading to Premium Membership and unlock official DMV tests. In addition, you will also receive a master cheat sheet which contains all your state’s DMV questions and answers. Premium membership also unlocks a smart tracker which keeps an inventory of all incorrectly answered questions for easy, fast and effective revision. Practice with our free tests or hit Upgrade button below for premium access and increase your chances of passing your DMV written exam.

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Quick Facts:

Number of Questions – 20

Passing Percentage – 80%

Test Type – Free Test

If your vehicle is stopped on a level surface.
If your vehicle is stopped on a slight incline.
If your vehicle's brakes are very hot.
If your vehicle's other braking systems seem to be working adequately.

Push down the brake pedal.
Open the hood.
Release air from the air storage tanks.
Open the door to the cab.

S-cam drum brake.
C-cam drum brake.
G-cam disc brake.
P-cam disc brake.

Orange
Yellow
Blue
Red

District of Columbia DMV CDL Air Brakes Quick Practice Test

District of Columbia DMV CDL Air Brakes Quick Practice Test For 2025

99.5% Pass Rate

Should not be used in cold weather.
Are helpful to remove water and oil from the air tanks.
Are used to move air to the brakes.

The air brakes should be used.
The vehicle should be placed in a low gear and the driver should use engine braking.
The driver should continually downshift instead of using the brakes.

If they are hot.
In the winter time.
If they are used frequently.