Air Brakes
This endorsement is required for driving a vehicle with air brakes. To receive this endorsement, applicants must pass a test. The test consists of 25 multiple choice questions. Each question has four answer choices. To pass, the applicant must answer at least 20 questions correctly. Test questions come from the Texas Commercial Motor Vehicle Drivers Handbook. Questions come from chapters 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 brake pedal is part of which braking system?
Explanation
The service brake system applies and releases the brakes when a driver presses the brake pedal while driving normally.
8. Most heavy-duty vehicles use ____ air brake systems.
Explanation
The majority of heavy-duty vehicles are equipped with dual air brake systems.
9. If using air tanks with manually operated drains, how often should you drain the tanks?
Explanation
To prevent the build up of oil and water in a vehicle's air tanks, manually operated air tank drains should be used at the end of each day of driving.
10. Where is the safety relief valve usually located?
Explanation
An air brake system's safety relief valve is located in the tank that is first to receive air from the compressor.
11. 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.
12. In a vehicle with dual parking control valves, once air pressure is lost and the spring brakes come on:
Explanation
