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.
An automatic wig wag will rise out of your view when the pressure in your system rises above what psi?
2.
A driver needs to be able to see a warning when the air pressure in the service air tanks falls below ______.
3.
In case of a low air situation, the spring brakes should come on at:
4.
The main factor in causing brake fade is:
5.
What negatively affects the braking power of a spring brake?
6.
To make sure that the spring brakes come on automatically, do all of the following except:
7.
When testing air leakage rates for single vehicles, initial loss rate should be less than:
8.
When increased application pressure to maintain the same speed becomes necessary, you should ______.
9.
Which braking system applies and releases the parking brakes when you use the parking brake control?
10.
In most newer vehicles, the parking brake control will be:
11.
What must the air pressure be, at minimum, in both parts of a dual air brake system?
12.
After the initial pressure drop, air leakage for single vehicles should be less than:
13.
Besides heat, another cause of brake fade is:
14.
When inspecting the air brake system, what particular item in the engine compartment should the driver pay specific attention to?
15.
Automatic air tanks _______.
16.
In dual air systems, how long should it take air pressure to build 85 to 100 psi?
17.
If one air system is very low on pressure _______.
18.
Stop light switches are necessary because ________.
19.
On large buses low pressure warning devices usually signal at ______.
20.
You should use the parking brake _____________.
21.
Air tanks should be drained:
22.
To check the air compressor governor's "cut in" and "cut out" pressures you need to _________.
23.
What is a wig wag ?
24.
The governor stops the compressor from pumping air at:
25.
On a long or steep downgrade, how should vehicle speed be primarily controlled?