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.
The most important thing to do when a low air pressure warning comes on is:
2.
Parking or emergency brakes of trucks and buses can be legally held on by ____ pressure.
3.
In case of a low air situation, the spring brakes should come on at:
4.
Your brakes are fading when:
5.
While applying the brakes, what tells the driver how much air pressure is being used?
6.
When the safety valve releases air this indicates ___________.
7.
When you release the brakes and reduce the air pressure what makes up for that air loss?
8.
When does the air compressor governor allow air to start pumping?
9.
If your truck or bus has dual parking control valves, you can use pressure from a separate tank to:
10.
If your truck has a dual air brake system, and one of the systems is low on pressure:
11.
After the initial pressure drop, air leakage for single vehicles should be less than:
12.
The air compressor governor controls:
13.
Under normal braking conditions, the vehicle:
14.
Brake drums (or discs) must not have cracks longer than ____ the width of the friction area.
15.
On newer vehicles what color is the parking brake knob?
16.
Automatic air tanks _______.
17.
At what level will the low air warning usually take effect?
18.
In dual air systems, how long should it take air pressure to build 85 to 100 psi?
19.
Why should you check the brake adjustment often?
20.
If one air system is very low on pressure _______.
21.
Some vehicles are equipped with a separate air tank used specifically to release the spring brakes in an emergency, called a:
22.
The safety valve in the air compressor tank is set to open at _____.
23.
You should use the parking brake _____________.
24.
What is proper braking technique for drivers travelling down a hill or any other downgrade?
25.
The governor stops the compressor from pumping air at: