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 Arkansas 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
1. 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.
2. What kind of brakes do most newer heavy-duty trucks use?
Explanation
Most newer heavy-duty vehicles use dual air brake systems. A dual air brake system has two separate air brake systems which use a single set of brake controls.
3. A low air pressure warning signal:
Explanation
Any vehicle with air brakes must be equipped with a low air pressure warning signal.
4. Truck tractors with air brakes built on or after March 1, 1997 must have:
Explanation
Truck tractors with air brakes built on or after March 1, 1997 must be equipped with Anti-Lock Braking Systems (ABS).
5. On a truck with air brakes, the braking system’s air compressor:
Explanation
In an air brake system, the air compressor pumps air into the air storage tanks. The air compressor is controlled by the air compressor governor.
6. When a brake pedal is pressed and the S-cam is turned, the S-cam:
Explanation
