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
A low air pressure warning signal is ________.
How far should manual slack adjusters move before they need to be adjusted?
When the engine is off and the parking brake released, a single vehicle air loss rate should be less than ________ psi in one minute.
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 vehicles are equipped with a control allowing you to apply the spring brakes gradually, called a:
Why is manually adjusting automatic slack adjusters dangerous?
If the low air pressure warning light comes on, you should:
In case of emergency stops, drivers should:
All of the following apply if the low air pressure warning signal does not work except:
How should the air leakage rate be tested?
Why does a heavily loaded vehicle need a longer distance to stop?
At minimum, a dual air system should build up to what psi in the primary and secondary systems?
Initial air leakage rate for combination vehicles should be:
If the air compressor has its own oil supply you should do what before driving?
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?
A warning to drivers behind you that the air brakes have been applied is the:
Vehicles with ABS have malfunction lamps that are what color?
On a long or steep downgrade, how should vehicle speed be primarily controlled?
The warning light and buzzer will come on when the air pressure in either system drops below what psi?
What happens when pressure is put on the air brakes?