Air Brakes
This endorsement is required for driving a vehicle with air brakes. To receive this endorsement, applicants must pass a written test. The test consists of 25 multiple choice questions. Each question has two, three or four answer choices. To pass, the applicant must answer at least 20 questions correctly. Test questions come from the South Carolina Commercial Driver License Manual. Questions come from the chapter covering: Air Brakes. The Air Brakes endorsement may be used with the Class A, B or C CDL.
Number of Question
Passing Score
7. The most common type of foundation brake used is the:
Explanation
The most common type of foundation brake is an s-cam drum brake.
8. Water and compressor oil are usually found in the compressed air within an air brake system. Water and compressor oil:
Explanation
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.
9. Using an Anti-Lock Braking System (ABS):
Explanation
An Anti-Lock Braking System (ABS) helps to provide additional control during hard braking, but does not necessarily shorten a vehicle's stopping distance.
10. On trucks and buses, where are ABS malfunction lamps located?
Explanation
Tractors, trucks, and buses with Anti-Lock Braking Systems (ABS) have yellow malfunction lamps located on their instrument panels. Trailers have yellow ABS malfunction lamps on their left side, either on the front or rear corner.
11. The parking brake should be:
Explanation
The parking brake should be applied every time you park your vehicle.
12. Foundation brakes are used:
Explanation
