# Free Kentucky CDL Air Brakes Practice Test 2023

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

Our CDL practice tests:
Based on 2021 KY commercial driver's license manual
Full answers + detailed explanations
Perfect for first-time, renewal applicants
KY CDL Air Brakes Test format:
25 questions
20 correct answers to pass
80% passing score
List of questions
1.
What can legally hold a parking or emergency brake in position for a truck, truck tractor, or bus?
2.
An air compressor can be cooled by _______.
3.
"A slack adjuster’s free play needs to be adjusted if it is more than about ______ when you pull hard on it."
4.
A low air pressure warning signal is ________.
5.
In case of a low air situation, the spring brakes should come on at:
6.
Total stopping distance for air brakes is longer than that for hydraulic brakes due to ______ distance.
7.
Excessive heat caused by using your brakes too often can also cause:
8.
The spring brakes used on the chambers in a straight truck will bring you to a stop when air pressure drops below ___ psi.
9.
Brake fade is caused by:
10.
In ideal conditions a truck or bus with air brakes going at 55 mph would require the stopping distance of how many feet?
11.
Generally, air governor cut-in should be at:
12.
What should a driver do when the low air pressure warning signal comes on?
13.
When parking a vehicle with a modulating control valve ________.
14.
To check the free play of manual slack adjusters of S-cam brakes, you should park on:
15.
The safety valve is set automatically when pressure is:
16.
The parking brake knob is usually:
17.
The manual adjustment of automatic slack adjusters is:
18.
How should you check that your service brakes are working properly?
19.
Pressing and releasing the brake pedal unnecessarily:
20.
On newer vehicles what color is the parking brake knob?
21.
Why do air brakes take longer to stop than hydraulic brakes?
22.
What is the purpose of a supply pressure gauge?
23.
A warning to drivers behind you that the air brakes have been applied is the:
24.
Required on all vehicles with air brakes, what tells the driver that air pressure is too low?
25.
What happens when pressure is put on the air brakes?