Free Missouri CDL Air Brakes Practice Test 2023

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

Our CDL practice tests:
Based on 2021 MO commercial driver's license manual
Full answers + detailed explanations
Perfect for first-time, renewal applicants
MO 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?
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.
A mechanical device that drops a low air warning into a drivers view is called a:
Your truck has a dual air system and one of the systems loses its pressure. What will happen?
The brake system that applies and releases the brakes when the driver uses the brake pedal is the ________ brake system.
The supply pressure gauge shows how much pressure:
To make sure that the spring brakes come on automatically, do all of the following except:
When the safety valve releases air this indicates ___________.
When checking the low pressure warning signal, it should turn on before the pressure drops below what psi?
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 is set automatically when pressure is:
If the spring brakes are on, when should you push the brake pedal?
Besides heat, another cause of brake fade is:
How should you check that your service brakes are working properly?
Compared to hydraulic brakes, air brakes add how much distance to an average 55 mph stop?
Repeatedly partially increasing and pressing the brake pedal may result in:
The most common problem found in roadside inspections is:
In dual air systems, how long should it take air pressure to build 85 to 100 psi?
When driving an older vehicle that has a manual front brake limiting valve, drivers should:
Stop light switches are necessary because ________.
Brake drums or discs _______.
During a normal drive, the spring brakes are held back by _____.
You should use the parking brake _____________.
Air tanks should be drained:
On a long or steep downgrade, how should vehicle speed be primarily controlled?