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 State of Delaware 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
13. The leakage rate for a single vehicle with air brakes should be no more than ____ in one minute during a static leakage test.
Explanation
When performing a static leakage test on a single vehicle with air brakes, the leakage rate should be no more than 2 psi in a minute. If the air leaks from the air brake system at a quicker rate, the vehicle should not be driven because something likely needs to be repaired.
14. The application pressure gauge:
Explanation
In an air brake system, the application pressure gauge shows how much air pressure is being applied to the brakes. Not all vehicles with an air brake system have this gauge.
15. ABS brakes:
Explanation
The purpose of an Anti-Lock Braking System (ABS) is to prevent a vehicle's wheels from locking up when the driver brakes hard on a slippery surface.
16. An alcohol evaporator in an air brake system:
Explanation
Some air brake systems include an evaporator that introduces alcohol into the system. The alcohol can help prevent ice from forming within the system.
17. Which type of brakes do most heavy-duty vehicles have?
Explanation
For safety, most heavy-duty vehicles are equipped with dual air brake systems.
18. What tells you how much pressure is in your vehicle's air tanks?
Explanation
