Air Brakes Endorsement Test | South Carolina 2025 #1

Train for FREE online with our South Carolina CDL air brake test. The official exam test consists of several obligatory parts, with all of them checking your knowledge of different blocks of road rules. If you need to obtain a SC Class A/Class B driver license in 2025, practice as much as possible. Free sample tests published on our website will help you check and improve your knowledge and boost your grades. Please bear in mind that the requirements for CDL may vary from state to state.

Number of Question 25

Passing Score 20

Number of Tests 20

1 . Water and compressor oil are usually found in the compressed air within an air brake system. Water and compressor oil:

Are necessary for the proper function of the air brake system.

Should be added if low.

Should be removed regularly.

Are not concerns.

Compressed air in an air brake system usually contains a certain amount of water and compressor oil. The water and oil can damage the brakes if left to accumulate in the system. Manually operated air tank drains must be opened daily to remove this build-up.

2 . To use the stab braking method, you should:

Apply the brakes completely until the wheels lock up, release the brakes until the wheels start rolling, then repeat the process.

Apply the brakes about halfway, but allow the wheels to keep rolling.

Apply the brakes completely until the wheels lock up and the vehicle stops.

Apply the emergency brake until the vehicle starts to slow.

The stab braking method for emergency stops involves fully applying the brakes until they lock up. The brakes are then released until the wheels start rolling, and then the process is repeated.

3 . If the low pressure warning light comes on while you are driving:

Braking will only be possible if there is still enough air in the tanks.

You can apply the brakes 14 times before the air in the system runs out.

You should continue to drive normally and check the brake system when it is convenient.

You should stay at least 100 feet away from other vehicles.

When driving a vehicle with air brakes, if the low air pressure warning light comes on, it is important for you to stop and safely park your vehicle as soon as possible. There may be a leak in the system. Controlled braking will remain possible only as long as there is enough air left in the tanks.

4 . To use the stab braking method in an emergency situation, you should:

Apply the brakes completely until the wheels lock up, release the brakes until the wheels start rolling, then repeat the process.

Apply the brakes about halfway, but keep the wheels rolling.

Fully apply the brakes, let the wheels lock up, and hold the brake pedal down, keeping the wheels locked until the vehicle stops.

Apply the emergency brake.

The stab braking method for emergency stops involves fully applying the brakes until they lock up. The brakes are then released until the wheels start rolling, then the process is repeated.

5 . What kind of force must emergency brakes use?

Air pressure

Mechanical

Heavy

Electrical

Because air pressure can eventually leak away, the emergency brakes in an air brake system must be held on by mechanical force.

6 . An air brake-equipped vehicle traveling at a speed of 55 mph under ideal driving conditions will need approximately ____ to come to a complete stop.

100 feet

250 feet

300 feet

450 feet

A vehicle's total stopping distance is made up of perception distance, reaction distance, brake lag distance, and braking distance. With all of these factors included, an air brake-equipped vehicle traveling at a speed of 55 mph under ideal driving conditions will need approximately 450 feet to come to a complete stop.

Study tip:

Reduce your study time from hours to minutes with a DMV exam “Cheat Sheet”

99.2% of people who use the cheat sheet pass the FIRST TIME

Click Here
Full Cheat Sheet

99.2%

99.2% of people who use the cheat sheet pass the FIRST TIME

2025 South Carolina | Frequently Asked Questions

A CDL Class A license in South Carolina allows drivers to operate any combination of vehicles with a Gross Combination Weight Rating (GCWR) of 26,001 lbs or more, provided the Gross Vehicle Weight Rating (GVWR) of the vehicle(s) being towed is over 10,000 lbs. This typically includes tractor-trailers and truck and trailer combinations.

A Class A CDL license in South Carolina allows you to operate vehicles such as tractor-trailers, truck and trailer combinations, tank vehicles, livestock carriers, and flatbeds. It includes any combination of vehicles with a Gross Combination Weight Rating (GCWR) of 26,001 lbs or more where the towed vehicle(s) exceed 10,000 lbs GVWR.

To obtain a Class A CDL license in South Carolina, you must be at least 18 years old (21 for interstate driving), possess a valid South Carolina driver's license, pass a vision test, and successfully complete knowledge and skills tests. You must also provide proof of identity, Social Security number, South Carolina residency, and clear a medical examination.

In South Carolina, you must be at least 18 years old to qualify for a Class A CDL license for intrastate driving (within South Carolina only). However, if you plan to drive interstate (across state lines or transporting materials from out of state), you must be at least 21 years old.

Specific endorsements aren't required for a Class A CDL license but they can provide additional driving privileges. Endorsements include: H (Hazardous Materials), N (Tank Vehicles), P (Passenger Vehicles), S (School Bus), T (Double/Triple Trailers). To get an endorsement, you must pass additional written and skills tests related to the specific type of vehicle.

The Class A CDL skills test in South Carolina encompasses three main sections: pre-trip inspection, basic controls, and on-road driving. The pre-trip inspection tests your knowledge on vehicle safety. The basic controls test assesses your ability to maneuver and control the vehicle. The on-road driving test evaluates your ability to drive the vehicle in various traffic conditions.

Yes, there are limitations for Class A CDL license holders in South Carolina. These limitations or restrictions relate to the type of vehicle you can drive, safety equipment needed, and in some cases, the time of day you can drive. Restrictions are marked on your CDL and may be removed by passing additional tests.

In South Carolina, the written Class A CDL test is primarily offered in English. However, some locations may offer the test in Spanish. It's recommended to contact your local DMV office to confirm language availability. Please note, all drivers must still have a basic understanding of English to ensure road safety.

Yes, you can request accommodations for the Class A CDL written test in South Carolina if you have a disability. The South Carolina Department of Motor Vehicles (SCDMV) is committed to ensuring that its services are accessible to all individuals. However, specific accommodations depend on the nature of the disability and must comply with federal regulations regarding commercial driving safety.

Yes, if you fail the Class A CDL written test in South Carolina, you can retake it. You must wait at least one day before retaking the test. However, keep in mind there may be additional fees associated with each retest. It's recommended to study thoroughly before reattempting to increase your chances of passing.