Free Colorado CDL Air Brakes Practice Test 2023

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 2021 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
An automatic wig wag will rise out of your view when the pressure in your system rises above what psi?
A driver needs to be able to see a warning when the air pressure in the service air tanks falls below ______.
To test air service brakes you should:
The air loss rate for a straight truck or bus with the engine off and the brakes on should not be more than:
A low pressure warning signal could be __________.
Excessive use of the service brakes results in overheating which can lead to:
When testing air leakage rates for single vehicles, initial loss rate should be less than:
Generally, air governor cut-in should be at:
When performing the controlled braking method for an emergency stop, you are _________.
What should a driver do when the low air pressure warning signal comes on?
In most newer vehicles, the parking brake control will be:
When does the air compressor governor allow air to start pumping?
Spring brakes will come on automatically, but the parking brake can also be applied:
It is not safe to drive a vehicle that has brake drums with cracks that are longer than _____ of the width of the friction area.
The safety valve reduces pressure at ___ psi.
The level at which the air compressor stops pumping air is:
The air compressor governor controls:
Total stopping distance with air brakes is Perception distance + Braking Distance + Brake Lag Distance +:
Average stopping distance under normal conditions at 55 mph is:
A device that limits the amount of air provided to the front brakes is a:
When inspecting the air brake system, what particular item in the engine compartment should the driver pay specific attention to?
Which of the following helps the stop light switch work?
How does the antilock brake system benefit the driver?
If air supply drops when driving, the tractor protection valve ________.
What does ABS stand for?