Free District of Columbia CDL Air Brakes Practice Test 2022

Do you need an Air Brakes endorsement or an L endorsement for your commercial driving license? The District of Columbia CDL Air Brake has some differences from other endorsements because your license will receive a mark of restriction if you fail the test. So having good preparation before exam day is very necessary. To ensure that our DC CDL practice test questions are relevant, all of them are based on the DC CDL Manual. Each question has a detailed explanation for you to thoroughly learn the format and the topic. Don't be afraid of having a restriction on your license. Let’s try with our CDL practice test to get ready to pass the District of Columbia CDL Air Brake Test now. 

Our CDL practice tests:
Based on 2022 DC commercial driver's license manual
Full answers + detailed explanations
Perfect for first-time, renewal applicants
DC CDL Air Brakes Test format:
25 questions
20 correct answers to pass
80% passing score
List of questions
1.
Air brakes consist of ________.
2.
A dual air brake system ________.
3.
To test the vehicle's service brakes, move the vehicle:
4.
The 3 individual systems of the air brakes are the service brakes, emergency brake, and:
5.
In a controlled braking emergency:
6.
When you need to apply more pressure to help your brakes work normally effectively, this means that your brakes are fading. Which of the following can cause fading brakes?
7.
Generally, air governor cut-in should be at:
8.
When the mechanical arm of a wig wag drops into your view that means the pressure in your system has dropped below what psi?
9.
When parking a vehicle with a modulating control valve ________.
10.
Some vehicles are equipped with a control allowing you to apply the spring brakes gradually, called a:
11.
The level at which the air compressor stops pumping air is:
12.
In a dual air brake system, the first system, supplying the rear brakes, is commonly known as the "primary" system, and the other as the:
13.
Pressing and releasing the brake pedal unnecessarily:
14.
In order to make contact with the brake drum, the brake pads and linings are pushed outward by the:
15.
In a dual air brake system, if the air pressure in one part of the system drops enough to set off the low air warning:
16.
In tractors and straight trucks spring brakes will come on fully when the air pressure drops to what range?
17.
The braking power of the spring brakes ______.
18.
The air tanks must be drained because:
19.
Stab braking should only be used:
20.
How does the antilock brake system benefit the driver?
21.
Why should air tanks be drained completely?
22.
The safety valve in the air compressor tank is set to open at _____.
23.
During a normal drive, the spring brakes are held back by _____.
24.
Vehicles with air brakes _________.
25.
What brake system uses part of the service and parking brake systems to stop the vehicle in the event of a brake system failure?