Free Colorado CDL Air Brakes Practice Test 2022

Do you need an 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 Colorado CDL practice test questions are based on the Colorado 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 with our free CDL Practice Test to get ready to pass the Colorado CDL Air Brake Test now. 

Our CDL practice tests:
Based on 2022 CO commercial driver's license manual
Full answers + detailed explanations
Perfect for first-time, renewal applicants
CO CDL Air Brakes Test format:
25 questions
20 correct answers to pass
80% passing score
List of questions
The parking or emergency brake on a heavy vehicle can only be held in position by something that cannot leak away, like:
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?
A low air pressure warning signal is ________.
During normal driving, spring brakes are usually held back by:
How far should manual slack adjusters move before they need to be adjusted?
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?
The ____ shows how much pressure is in the air tanks.
When you need to apply more pressure to help your brakes work normally effectively, this means that your brakes are fading. Which of the following can cause fading brakes?
Normally during anti-lock braking, the driver:
When parking a vehicle with a modulating control valve ________.
"Some air brake systems have an alcohol evaporator. What may happen if you don’t keep the proper level of alcohol?"
If the spring brakes are on, when should you push the brake pedal?
In case of emergency stops, drivers should:
If your vehicle has an alcohol evaporator, every day during cold weather you should:
Repeatedly partially increasing and pressing the brake pedal may result in:
All of the following apply if the low air pressure warning signal does not work except:
How should the air leakage rate be tested?
At minimum, a dual air system should build up to what psi in the primary and secondary systems?
On large buses low pressure warning devices usually signal at ______.
Air tanks should be drained:
What is proper braking technique for drivers travelling down a hill or any other downgrade?
To avoid damaging the brakes, what should you never do while the spring brakes are applied?
Vehicles with ABS have malfunction lamps that are what color?
On a long or steep downgrade, how should vehicle speed be primarily controlled?
What happens when pressure is put on the air brakes?