# Free Maryland CDL Air Brakes Practice Test 2023

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

Our CDL practice tests:
Based on 2021 MD commercial driver's license manual
Perfect for first-time, renewal applicants
MD CDL Air Brakes Test format:
25 questions
80% passing score
List of questions
1.
An air compressor can be cooled by _______.
2.
When is it OK to leave your truck unattended without applying the parking brakes and choking the wheels?
3.
Excessive heat caused by using your brakes too often can also cause:
4.
The spring brakes used on the chambers in a straight truck will bring you to a stop when air pressure drops below ___ psi.
5.
The supply pressure gauge shows how much pressure:
6.
7.
When the air system is low ________.
8.
Some vehicles are equipped with a control allowing you to apply the spring brakes gradually, called a:
9.
When your brake's main air pressure is lost ________.
10.
When does the air compressor governor allow air to start pumping?
11.
12.
What is a \"Wig Wag\"
13.
The air compressor governor controls:
14.
Besides heat, another cause of brake fade is:
15.
In a dual air brake system, the first system, supplying the rear brakes, is commonly known as the "primary" system, and the other as the:
16.
Why does a heavily loaded vehicle need a longer distance to stop?
17.
Brake drums should not have cracks longer than what length?
18.
When driving an older vehicle that has a manual front brake limiting valve, drivers should:
19.
Stop light switches are necessary because ________.
20.
If the air compressor has its own oil supply you should do what before driving?
21.
What is used to put alcohol into the system and reduce ice risk?
22.
The parking brake should be used:
23.
Typically, at what psi does the air compressor governor stop the compressor from pumping air?
24.
What is an alternative name for a brake pedal?
25.
Required on all vehicles with air brakes, what tells the driver that air pressure is too low?