Do you need an Oklahoma Air Brakes endorsement or an L endorsement for your commercial driving license? The Oklahoma 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 questions are relevant, all of our CDL practice test packs are based on the Oklahoma 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 our Oklahoma CDL Practice Test to get ready to pass the Oklahoma CDL Air Brake Test now. 

Our CDL practice tests:
Based on 2022 OK commercial driver's license manual
Full answers + detailed explanations
Perfect for first-time, renewal applicants
OK CDL Air Brakes Test format:
25 questions
20 correct answers to pass
80% passing score
List of questions
1.
When is it OK to leave your truck unattended without applying the parking brakes and choking the wheels?
2.
The air brake lag distance at 55 mph on dry pavement adds about ____ feet.
3.
Air tanks need to be drained ______.
4.
Your truck or bus has a dual air brake system. If a low air pressure warning comes on for only one system, what should you do?
5.
If your vehicle has an alcohol evaporator, it is there to:
6.
The application pressure gauge shows how much air pressure you:
7.
Normally during anti-lock braking, the driver:
8.
What should a driver do when the low air pressure warning signal comes on?
9.
What type of brakes pushes a wedge between the ends of two brake shoes to stop the vehicle?
10.
What happens when your brake drums get very hot?
11.
Why is manually adjusting automatic slack adjusters dangerous?
12.
If the low air pressure warning light comes on, you should:
13.
The parking brake should not be used when wet in freezing temperatures, or:
14.
The S-cam:
15.
To stop the vehicle, the brake shoes and linings are pushed against:
16.
To test the parking brake, stop the vehicle, put the parking brake on, and:
17.
The brake pedal in an air brake system _______.
18.
Why does a heavily loaded vehicle need a longer distance to stop?
19.
How should the air leakage rate be tested?
20.
In tractors and straight trucks spring brakes will come on fully when the air pressure drops to what range?
21.
At minimum, a dual air system should build up to what psi in the primary and secondary systems?
22.
The braking power of the spring brakes ______.
23.
Vehicles without automatic air tank drains need to be checked manually to remove ________?
24.
Typically, at what psi does the air compressor governor stop the compressor from pumping air?
25.
Manual air tank drains require: