# Free Minnesota CDL Air Brakes Practice Test 2023

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

Our CDL practice tests:
Based on 2021 MN commercial driver's license manual
Perfect for first-time, renewal applicants
MN CDL Air Brakes Test format:
25 questions
80% passing score
List of questions
1.
The parking or emergency brake on a heavy vehicle can only be held in position by something that cannot leak away, like:
2.
Your truck or bus has a dual air brake system. If a low-pressure warning comes on for only one system, what should you do?
3.
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?
4.
The reduced stopping power caused by overuse of the service brakes and excessive heat is called:
5.
A low pressure warning signal could be __________.
6.
If your vehicle has an alcohol evaporator, it is there to:
7.
If you must make an emergency stop, you should brake so you:
8.
When the air system is low ________.
9.
The type of brakes that clamp the rotor between the brake shoes is:
10.
When the safety valve releases air this indicates ___________.
11.
When you release the brakes and reduce the air pressure what makes up for that air loss?
12.
What type of brakes pushes a wedge between the ends of two brake shoes to stop the vehicle?
13.
What happens when your brake drums get very hot?
14.
The level at which the air compressor stops pumping air is:
15.
If the low air pressure warning light comes on, you should:
16.
When checking the air pressure buildup, pressure should build:
17.
Brake drums (or discs) must not have cracks longer than ____ the width of the friction area.
18.
The most common problem found in roadside inspections is:
19.
The use of brakes on a long and steep downgrade under normal conditions is only a supplement to:
20.
If you need to make an emergency stop, you should brake so that you can ________.
21.
On newer vehicles what color is the parking brake knob?
22.
Brake drums or discs _______.
23.
Why should air tanks be drained completely?
24.
What does the air compressor governor control?
25.
Vehicles without automatic air tank drains need to be checked manually to remove ________?