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.
What can legally hold a parking or emergency brake in position for a truck, truck tractor, or bus?
2.
In case of emergency when driving a vehicle equipped with dual parking control valves, you should:
3.
At 55 mph on dry pavement, the air brake lag distance is how many feet?
4.
An air brake system is fully charged at what psi?
5.
In a controlled braking emergency:
6.
The main factor in causing brake fade is:
7.
What negatively affects the braking power of a spring brake?
8.
When the air system is low ________.
9.
Generally, air governor cut-in should be at:
10.
When your brake's main air pressure is lost ________.
11.
To check the free play of manual slack adjusters of S-cam brakes, you should park on:
12.
Besides heat, another cause of brake fade is:
13.
Average stopping distance under normal conditions at 55 mph is:
14.
After the initial pressure drop, air leakage for combination vehicles should be less than:
15.
Controlled braking is only possible _________.
16.
The service brake system ________.
17.
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:
18.
If your vehicle has an alcohol evaporator, the evaporator's purpose is to _____.
19.
The air tanks must be drained because:
20.
Why do air brakes take longer to stop than hydraulic brakes?
21.
How often should alcohol containers be checked during cold weather?
22.
On a long or steep downgrade, how should vehicle speed be primarily controlled?
23.
What does ABS stand for?
24.
What is the function of a safety valve?
25.
To test the parking brake you should _______.