# 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.
A driver needs to be able to see a warning when the air pressure in the service air tanks falls below ______.
2.
If you do not have automatic tank drains, how often should you drain the oil and water from the bottom of compressed air storage tanks?
3.
The reduced stopping power caused by overuse of the service brakes and excessive heat is called:
4.
The air brake lag distance at 55 mph on dry pavement adds about ____ feet.
5.
Parking or emergency brakes of trucks and buses can be legally held on by ____ pressure.
6.
Excessive heat caused by using your brakes too often can also cause:
7.
Your truck has a dual air system and one of the systems loses its pressure. What will happen?
8.
When checking the low pressure warning signal, it should turn on before the pressure drops below what psi?
9.
When using a vehicle with air brakes, the parking needs to be used _______.
10.
"Some air brake systems have an alcohol evaporator. What may happen if you don’t keep the proper level of alcohol?"
11.
The parking brake knob is usually:
12.
If air pressure is not built up within the correct amount of time, then:
13.
In order to make contact with the brake drum, the brake pads and linings are pushed outward by the:
14.
How should the air leakage rate be tested?
15.
In tractors and straight trucks spring brakes will come on fully when the air pressure drops to what range?
16.
Why should you drain water from compressed air tanks?
17.
Some vehicles are equipped with a separate air tank used specifically to release the spring brakes in an emergency, called a:
18.
Brake linings should not be _______.
19.
The braking power of the spring brakes ______.
20.
On newer vehicles, the parking brake control knob is typically yellow, but on older vehicles, the parking brake might be what color?
21.
Vehicles without automatic air tank drains need to be checked manually to remove ________?
22.
On a long or steep downgrade, how should vehicle speed be primarily controlled?
23.
In a dual air brake system, one system will typically control the rear brakes, and the other:
24.
What is an alternative name for a brake pedal?
25.
Required on all vehicles with air brakes, what tells the driver that air pressure is too low?