# Free Mississippi CDL Air Brakes Practice Test 2023

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

Our CDL practice tests:
Based on 2021 MS commercial driver's license manual
Perfect for first-time, renewal applicants
MS CDL Air Brakes Test format:
25 questions
80% passing score
List of questions
1.
The most common type of foundation brakes are:
2.
The air brake lag distance at 55 mph on dry pavement adds about ____ feet.
3.
The driver must be able to see a low air pressure warning which comes on before pressure in the service air tanks falls below ____ psi.
4.
At 55 mph on dry pavement, the air brake lag distance is how many feet?
5.
Your truck or bus has a dual air brake system. If a low air pressure warning comes on for only one system, what should you do?
6.
If your truck has a properly functioning dual air brake system and minimum size air tanks, the air pressure should build up from 85 to 100 psi within how many seconds?
7.
On a long or steep downgrade, the foot brakes should be used:
8.
Excessive heat caused by using your brakes too often can also cause:
9.
10.
In ideal conditions a truck or bus with air brakes going at 55 mph would require the stopping distance of how many feet?
11.
Another name for the brake pedal is the "foot valve", or:
12.
When checking the low pressure warning signal, it should turn on before the pressure drops below what psi?
13.
When parking a vehicle with a modulating control valve ________.
14.
The safety valve reduces pressure at ___ psi.
15.
The parking brake knob is usually:
16.
What must the air pressure be, at minimum, in both parts of a dual air brake system?
17.
The level at which the air compressor stops pumping air is:
18.
The air compressor governor controls:
19.
In case of air pressure loss, a mechanical means of preventing the vehicle from moving is called:
20.
The use of brakes on a long and steep downgrade under normal conditions is only a supplement to:
21.
How are brakes designed?
22.
If the air compressor has its own oil supply you should do what before driving?
23.
On newer vehicles, the parking brake control knob is typically yellow, but on older vehicles, the parking brake might be what color?
24.
Vehicles without automatic air tank drains need to be checked manually to remove ________?
25.
In a dual air brake system, one system will typically control the rear brakes, and the other: