Free Illinois CDL Air Brakes Practice Test 2022

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 2022 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
List of questions
1.
To test air service brakes you should:
2.
When inspecting air brakes:
3.
A low air pressure warning signal is ________.
4.
"A slack adjuster’s free play needs to be adjusted if it is more than about ______ when you pull hard on it."
5.
Parking or emergency brakes of trucks and buses can be legally held on by ____ pressure.
6.
The main factor in causing brake fade is:
7.
Brake fade is caused by:
8.
When increased application pressure to maintain the same speed becomes necessary, you should ______.
9.
When you release the brakes and reduce the air pressure what makes up for that air loss?
10.
Air governor cut-out should be at around:
11.
When stab braking if you re-apply the brakes before the wheels start rolling, __________.
12.
Some vehicles are equipped with a control allowing you to apply the spring brakes gradually, called a:
13.
Why is manually adjusting automatic slack adjusters dangerous?
14.
What is a \"Wig Wag\"
15.
With air brake vehicles, the parking brakes should be used:
16.
Brake drums (or discs) must not have cracks longer than ____ the width of the friction area.
17.
The most common problem found in roadside inspections is:
18.
In dual air systems, how long should it take air pressure to build 85 to 100 psi?
19.
Brake drums should not have cracks longer than what length?
20.
In a dual air brake system, if the air pressure in one part of the system drops enough to set off the low air warning:
21.
Stop light switches are necessary because ________.
22.
How does the antilock brake system benefit the driver?
23.
Air tanks should be drained:
24.
What brake system uses part of the service and parking brake systems to stop the vehicle in the event of a brake system failure?
25.
Vehicles with ABS have malfunction lamps that are what color?