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
The parking or emergency brake on a heavy vehicle can only be held in position by something that cannot leak away, like:
What can legally hold a parking or emergency brake in position for a truck, truck tractor, or bus?
In case of emergency when driving a vehicle equipped with dual parking control valves, you should:
An application pressure gauge shows how much air you are applying to the brakes. Increased application pressure to maintain the same speed indicates that __________.
The reduced stopping power caused by overuse of the service brakes and excessive heat is called:
The air brake lag distance at 55 mph on dry pavement adds about ____ feet.
Emergency stab braking is:
Under normal conditions, in order to engage the parking brakes the driver should:
The 3 individual systems of the air brakes are the service brakes, emergency brake, and:
To stop the vehicle, air brakes systems use:
The type of brakes that clamp the rotor between the brake shoes is:
When should the spring brakes activate?
What should a driver do when the low air pressure warning signal comes on?
When you need to depress the brakes harder and harder just to maintain the same speed this means ______.
To check the free play of manual slack adjusters of S-cam brakes, you should park on:
What is a \"Wig Wag\"
After the initial pressure drop, air leakage for single vehicles should be less than:
You should avoid using the parking brake when _______.
The brake pedal in an air brake system _______.
Automatic air tanks _______.
If your vehicle has an alcohol evaporator, the evaporator's purpose is to _____.
What is proper braking technique for drivers travelling down a hill or any other downgrade?
The governor stops the compressor from pumping air at:
Required on all vehicles with air brakes, what tells the driver that air pressure is too low?
Water and oil _______.