Air Brakes #2
Air Brakes Endorsement Test | South Carolina 2026 #2 Page 3 of 4
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 2026, 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.
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13 . What can happen if the air pressure gets too low in an air brake system?
The brakes will be very sensitive.
Pressing and releasing the brake pedal unnecessarily can let air out faster than the compressor can replace it, reducing the available air pressure. If the air pressure in an air brake system gets too low, the brakes will no longer work.
14 . At what psi is the safety valve set to open?
500 psi
In an air brake system, the first tank that receives compressed air has a safety valve that releases air if the pressure gets too high. It is usually set to open at 150 psi. If the valve must open, there is a fault in the system that should be repaired by a mechanic.
15 . An alcohol evaporator in an air brake system:
Some air brake systems include an evaporator that introduces alcohol into the system. The alcohol can help prevent ice from forming within the system.
16 . A low air pressure warning signal should activate:
When tank pressure falls below 5 psi.
In an air brake system, a low air pressure warning signal must come on if air pressure in the tanks falls below 60 psi. This warning signal may come in the form of a light, a buzzer, or a wig wag.
17 . 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.
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.
18 . What color light indicates a vehicle's ABS is not working?
On vehicles with Anti-Lock Braking Systems (ABS), yellow malfunction lamps alert the driver to ABS malfunction.
2026 South Carolina | Frequently Asked Questions
To acquire a CDL Passenger endorsement in South Carolina, you must first hold a valid CDL. Then, you need to pass the Passenger Transport Test, which covers the special rules and skills for carrying passengers. Lastly, you must pass a driving test in a vehicle similar to one you'll be operating with passengers.
To obtain a CDL Passenger license in South Carolina, you must be at least 21 years old, hold a valid Commercial Driver’s License (CDL), pass a Passenger Transport written test, and complete a skills test in the type of vehicle you'll be driving. A background check and medical examination may also be required.
While South Carolina doesn't require specific training to secure a CDL Passenger endorsement, it's beneficial to have experience driving large vehicles. However, you must pass the Passenger Transport written test and a skills test in a passenger vehicle. Training programs can help prepare you for these tests and enhance your driving skills.
Yes, in South Carolina, to obtain a CDL Passenger endorsement, you must pass the Passenger Transport written knowledge test. This test focuses on specific rules and safety guidelines for transporting passengers. The test covers areas like inspecting passenger vehicles, loading/unloading passengers, and emergency procedures. You may also need to take a road skills test in a passenger vehicle.
During the CDL Passenger endorsement assessment, you'll need to demonstrate your ability to inspect your vehicle, manage passenger entry and exit, handle emergencies, and navigate different road types safely. You'll also need to show proficiency in maneuvering the vehicle through turns, intersections, and various traffic conditions.
No, it's illegal to transport passengers commercially without a valid CDL Passenger endorsement in South Carolina. This endorsement ensures that drivers have the necessary knowledge and skills to safely transport passengers. Violating this can result in fines, loss of commercial driving privileges, and even legal consequences.
Yes, you can add the CDL Passenger endorsement to your existing commercial driver's license. You don't need to apply for a new license. However, you will need to pass the passenger endorsement knowledge test and, in some cases, a skills test. Check with the South Carolina DMV for specific requirements.
Yes, there are restrictions for drivers with a CDL Passenger endorsement. They must comply with all federal and state regulations, including hours of service rules. They cannot transport more passengers than the vehicle is designed for, and they must ensure that all passengers use seat belts. Violation of these rules can lead to fines or loss of endorsement.
Yes, to obtain a CDL Passenger endorsement in South Carolina, you must be at least 21 years old. This is a federal requirement for any driver operating a commercial vehicle that crosses state lines. However, if you're only driving within South Carolina, you may be able to get a CDL at age 18. Always check with the South Carolina DMV for specific state requirements.
With a CDL Passenger endorsement in South Carolina, you can operate commercial vehicles designed to carry 16 or more passengers, including the driver. This includes buses, school buses, shuttle vans, and some types of limousines. Remember, the exact type of vehicle you can drive also depends on other endorsements and restrictions on your CDL.