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 three or four answer choices. To pass, the applicant must answer at least 20 questions correctly. Test questions come from the Mississippi Professional Driver’s 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
13. If using air tanks with manually operated drains, how often should you drain the tanks?
Explanation
In an air brake system with manually operated drains, the tanks should be drained at the end of each day of driving.
14. Air tank drains:
Explanation
In an air brake system, the air tanks are equipped with drains that allow water and compressor oil to be removed from the system. If allowed to build up, water and compressor oil can damage an air brake system.
15. All air tanks must include:
Explanation
Air brake system tanks must contain drain valves. These valves are used to drain accumulated oil and water from the tanks and may be either manually or automatically operated.
16. What is removed when an air tank is drained?
Explanation
In an air brake system, air tanks have drains to remove accumulations of water and compressor oil. Allowing water and oil to accumulate in the system could cause damage to the brakes.
17. To stop a vehicle using air brakes:
Explanation
To stop normally in a vehicle with air brakes, press down the brake pedal.
18. The air compressor is connected to the:
Explanation
