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.
The driver must be able to see a low air pressure warning which comes on before pressure in the service air tanks fall below ____ psi.
2.
When is it OK to leave your truck unattended without applying the parking brakes and choking the wheels?
3.
How far should manual slack adjusters move before they need to be adjusted?
4.
At 55 mph on dry pavement, the air brake lag distance is how many feet?
5.
A dual air brake system ________.
6.
If your truck has a properly functioning dual air brake system and minimum size air tanks, the air pressure should build up from 85 to 100 psi within how many seconds?
7.
On a long or steep downgrade, the foot brakes should be used:
8.
In a controlled braking emergency:
9.
While applying the brakes, what tells the driver how much air pressure is being used?
10.
When should the spring brakes activate?
11.
When you need to depress the brakes harder and harder just to maintain the same speed this means ______.
12.
When does the air compressor governor allow air to start pumping?
13.
If you must make an emergency stop, you should brake so you:
14.
If the low air warning comes on while you are driving, you should:
15.
All of the following are factors in total stopping distance except:
16.
The air compressor governor controls:
17.
Pushing the brake pedal down harder __________.
18.
How are brakes designed?
19.
If your vehicle has an alcohol evaporator, the evaporator's purpose is to _____.
20.
Why should air tanks be drained completely?
21.
During a normal drive, the spring brakes are held back by _____.
22.
What is used to put alcohol into the system and reduce ice risk?
23.
The spring brakes of a tractor will come on when the air pressure falls within _______.
24.
Required on all vehicles with air brakes, what tells the driver that air pressure is too low?
25.
Water and oil _______.