# Free South Carolina CDL Air Brakes Practice Test 2023

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

Our CDL practice tests:
Based on 2021 SC commercial driver's license manual
Perfect for first-time, renewal applicants
SC CDL Air Brakes Test format:
25 questions
80% passing score
List of questions
1.
An air compressor can be cooled by _______.
2.
The safety valve discharges automatically at the pressure of:
3.
In case of emergency when driving a vehicle equipped with dual parking control valves, you should:
4.
The air brake lag distance at 55 mph on dry pavement adds about ____ feet.
5.
At 55 mph on dry pavement, the air brake lag distance is how many feet?
6.
Under normal conditions, in order to engage the parking brakes the driver should:
7.
A mechanical device that drops a low air warning into a drivers view is called a:
8.
What negatively affects the braking power of a spring brake?
9.
10.
If you must make an emergency stop, you should brake so you:
11.
Spring brakes will come on automatically, but the parking brake can also be applied:
12.
Air braking takes more time than hydraulic braking because:
13.
14.
Under normal braking conditions, the vehicle:
15.
The most common problem found in roadside inspections is:
16.
Why should you check the brake adjustment often?
17.
In a dual air brake system, if the air pressure in one part of the system drops enough to set off the low air warning:
18.
The braking power of the spring brakes ______.
19.
The safety valve in the air compressor tank is set to open at _____.
20.
If the air compressor has its own oil supply you should do what before driving?
21.
On large buses low pressure warning devices usually signal at ______.
22.
During a normal drive, the spring brakes are held back by _____.
23.
Vehicles with air brakes _________.
24.
Vehicles without automatic air tank drains need to be checked manually to remove ________?
25.
Required on all vehicles with air brakes, what tells the driver that air pressure is too low?