Free Oregon CDL Air Brakes Practice Test 2023

Do you need an Oregon Air Brakes endorsement or an L endorsement for your commercial driving license? The Oregon 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 Oregon 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 Oregon CDL Practice Test to get ready to pass the Oregon CDL Air Brake Test now. 

Our CDL practice tests:
Based on 2021 OR commercial driver's license manual
Full answers + detailed explanations
Perfect for first-time, renewal applicants
OR CDL Air Brakes Test format:
25 questions
20 correct answers to pass
80% passing score
List of questions
"A slack adjuster’s free play needs to be adjusted if it is more than about ______ when you pull hard on it."
An application pressure gauge shows how much air you are applying to the brakes. Increased application pressure to maintain the same speed indicates that __________.
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?
The driver must be able to see a low air pressure warning which comes on before pressure in the service air tanks falls below ____ psi.
The most important thing to do when a low air pressure warning comes on is:
To test the vehicle's service brakes, move the vehicle:
On a long or steep downgrade, the foot brakes should be used:
The low air pressure warning signal indicates:
When parking a vehicle with a modulating control valve ________.
If the air compressor should develop a leak, what keeps the air in the tanks?
If your truck or bus has dual parking control valves, you can use pressure from a separate tank to:
When brakes are applied, the brake shoes will press against the:
After the initial pressure drop, air leakage for single vehicles should be less than:
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:
With air brake vehicles, the parking brakes should be used:
The use of brakes on a long and steep downgrade under normal conditions is only a supplement to:
When inspecting the air brake system, what particular item in the engine compartment should the driver pay specific attention to?
The brake pedal in an air brake system _______.
Why does a heavily loaded vehicle need a longer distance to stop?
Brake drums should not have cracks longer than what length?
Stab braking should only be used:
What does the air compressor governor control?
What is used to put alcohol into the system and reduce ice risk?
Manual air tank drains require:
Vehicles with ABS have malfunction lamps that are what color?