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
Full answers + detailed explanations
Perfect for first-time, renewal applicants
SC CDL Air Brakes Test format:
25 questions
20 correct answers to pass
80% passing score
List of questions
A low pressure warning signal could be __________.
When is it OK to leave your truck unattended without applying the parking brakes and choking the wheels?
How far should manual slack adjusters move before they need to be adjusted?
In case of a low air situation, the spring brakes should come on at:
The 3 individual systems of the air brakes are the service brakes, emergency brake, and:
Your truck has a dual air system and one of the systems loses its pressure. What will happen?
The main factor in causing brake fade is:
While applying the brakes, what tells the driver how much air pressure is being used?
If you must make an emergency stop, you should brake so you:
When the mechanical arm of a wig wag drops into your view that means the pressure in your system has dropped below what psi?
When parking a vehicle with a modulating control valve ________.
In most newer vehicles, the parking brake control will be:
Why is manually adjusting automatic slack adjusters dangerous?
If you are driving down a steep downgrade and have reached your safe speed of 40 mph, you would apply the service brake until your speed dropped to ____ mph.
How should you check that your service brakes are working properly?
If air pressure is not built up within the correct amount of time, then:
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:
Compared to hydraulic brakes, air brakes add how much distance to an average 55 mph stop?
How should the air leakage rate be tested?
Brake drums should not have cracks longer than what length?
The air compressor is connected to the engine through ______.
Why do air brakes take longer to stop than hydraulic brakes?
What is the purpose of a supply pressure gauge?
On a long or steep downgrade, how should vehicle speed be primarily controlled?
To test the parking brake you should _______.