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.
In case of emergency when driving a vehicle equipped with dual parking control valves, you should:
2.
At 55 mph on dry pavement, the air brake lag distance is how many feet?
3.
A mechanical device that drops a low air warning into a drivers view is called a:
4.
On a long or steep downgrade, the foot brakes should be used:
5.
When should the spring brakes activate?
6.
What should a driver do when the low air pressure warning signal comes on?
7.
Average stopping distance under normal conditions at 55 mph is:
8.
To stop the vehicle, the brake shoes and linings are pushed against:
9.
In case of air pressure loss, a mechanical means of preventing the vehicle from moving is called:
10.
To test the parking brake, stop the vehicle, put the parking brake on, and:
11.
The service brake system ________.
12.
On newer vehicles what color is the parking brake knob?
13.
Why should you check the brake adjustment often?
14.
Which of the following helps the stop light switch work?
15.
The air compressor is connected to the engine through ______.
16.
Some vehicles are equipped with a separate air tank used specifically to release the spring brakes in an emergency, called a:
17.
Brake drums or discs _______.
18.
If the air compressor has its own oil supply you should do what before driving?
19.
How often should alcohol containers be checked during cold weather?
20.
What is used to put alcohol into the system and reduce ice risk?
21.
What is the purpose of a supply pressure gauge?
22.
In a dual air brake system, one system will typically control the rear brakes, and the other:
23.
What is an alternative name for a brake pedal?
24.
Vehicles with air brakes have pressure gauges connected to the _______.
25.
To test the parking brake you should _______.