# 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
Perfect for first-time, renewal applicants
OR CDL Air Brakes Test format:
25 questions
80% passing score
List of questions
1.
To test air service brakes you should:
2.
The most common type of foundation brakes are:
3.
The air compressor stops pumping air at what psi?
4.
Total stopping distance for air brakes is longer than that for hydraulic brakes due to ______ distance.
5.
In ideal conditions a truck or bus with air brakes going at 55 mph would require the stopping distance of how many feet?
6.
What negatively affects the braking power of a spring brake?
7.
When the air system is low ________.
8.
When the mechanical arm of a wig wag drops into your view that means the pressure in your system has dropped below what psi?
9.
Which braking system applies and releases the parking brakes when you use the parking brake control?
10.
It is not safe to drive a vehicle that has brake drums with cracks that are longer than _____ of the width of the friction area.
11.
What happens when your brake drums get very hot?
12.
All of the following are factors in total stopping distance except:
13.
When checking the air pressure buildup, pressure should build:
14.
The air compressor governor controls:
15.
All of the following apply if the low air pressure warning signal does not work except:
16.
If you need to make an emergency stop, you should brake so that you can ________.
17.
When driving an older vehicle that has a manual front brake limiting valve, drivers should:
18.
The air tanks must be drained because:
19.
Why do air brakes take longer to stop than hydraulic brakes?
20.
Brake drums or discs _______.
21.
The belt of a belt-driven air compressor should be ________.
22.
Spring brakes are applied:
23.
To avoid damaging the brakes, what should you never do while the spring brakes are applied?
24.
What is the purpose of an air storage tank?
25.
What does ABS stand for?