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 2021 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
An automatic wig wag will rise out of your view when the pressure in your system rises above what psi?
The reduced stopping power caused by overuse of the service brakes and excessive heat is called:
The proper use of the brakes when going down a long steep grade after selecting a proper gear is to brake until your speed is about ____ below the posted speed and release your brake.
Your truck has a dual air system and one of the systems loses its pressure. What will happen?
The brake system that applies and releases the brakes when the driver uses the brake pedal is the ________ brake system.
The low air pressure warning signal indicates:
The type of brakes that clamp the rotor between the brake shoes is:
What is the purpose of an antilock braking system (ABS)?
When stab braking if you re-apply the brakes before the wheels start rolling, __________.
If you must make an emergency stop, you should brake so you:
All of the following are factors in total stopping distance except:
Air braking takes more time than hydraulic braking because:
The manual adjustment of automatic slack adjusters is:
Pressing and releasing the brake pedal unnecessarily:
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:
Compared to hydraulic brakes, air brakes add how much distance to an average 55 mph stop?
The most common problem found in roadside inspections is:
All of the following apply if the low air pressure warning signal does not work except:
When inspecting the air brake system, what particular item in the engine compartment should the driver pay specific attention to?
The air compressor is connected to the engine through ______.
Which of the following helps the stop light switch work?
How does the antilock brake system benefit the driver?
To check the air compressor governor's "cut in" and "cut out" pressures you need to _________.
What brake system uses part of the service and parking brake systems to stop the vehicle in the event of a brake system failure?
What is a wig wag ?