Free Illinois CDL Air Brakes Practice Test 2023

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

Our CDL practice tests:
Based on 2021 IL commercial driver's license manual
Full answers + detailed explanations
Perfect for first-time, renewal applicants
IL CDL Air Brakes Test format:
25 questions
20 correct answers to pass
80% passing score
Study now
List of questions
1.
In case of emergency when driving a vehicle equipped with dual parking control valves, you should:
2.
During normal driving, spring brakes are usually held back by:
3.
The air brake lag distance at 55 mph on dry pavement adds about ____ feet.
4.
All air brake equipped vehicles have:
5.
Air tanks need to be drained ______.
6.
To test the vehicle's service brakes, move the vehicle:
7.
The spring brakes used on the chambers in a straight truck will bring you to a stop when air pressure drops below ___ psi.
8.
The brake system that applies and releases the brakes when the driver uses the brake pedal is the ________ brake system.
9.
The low air pressure warning signal indicates:
10.
To make sure that the spring brakes come on automatically, do all of the following except:
11.
Another name for the brake pedal is the "foot valve", or:
12.
When the mechanical arm of a wig wag drops into your view that means the pressure in your system has dropped below what psi?
13.
What is the purpose of an antilock braking system (ABS)?
14.
To check the free play of manual slack adjusters of S-cam brakes, you should park on:
15.
If the low air pressure warning light comes on, you should:
16.
Which of these is NOT a proper time to apply the parking brakes?
17.
To stop the vehicle, the brake shoes and linings are pushed against:
18.
When inspecting the air brake system, what particular item in the engine compartment should the driver pay specific attention to?
19.
The brake pedal in an air brake system _______.
20.
Brake drums or discs _______.
21.
You should use the parking brake _____________.
22.
The governor stops the compressor from pumping air at:
23.
Typically, at what psi does the air compressor governor stop the compressor from pumping air?
24.
What is the function of a safety valve?
25.
What happens when pressure is put on the air brakes?
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