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. To pass, the applicant must answer at least 20 questions correctly. Test questions come from the Ohio Commercial Driver’s License Manual. Questions come from 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 parking brake in a newer vehicle is applied by:
Explanation
In newer vehicles with air brakes, the parking brake is controlled by a yellow, diamond-shaped knob. The driver should pull the knob outward to apply the parking brakes and push the knob inward to release them.
8. An emergency brake must be controlled by:
Explanation
All trucks, truck tractors, and buses must be equipped with emergency brakes and parking brakes. Because air pressure can eventually leak away, emergency and parking brakes should be held on by mechanical force.
9. The ____ between an air compressor and reservoir tank prevents air from escaping if the air compressor has a leak.
Explanation
A one-way check valve is required to be between an air compressor and the first main reservoir. This valve prevents air from escaping the system if the air compressor develops a leak.
10. When stopping in an emergency situation, you should:
Explanation
If you need to make an emergency stop, you can use either the controlled braking method or the stab braking method. It's important to brake in a way that keeps your vehicle in a straight line but will still allow you to turn if necessary.
11. If the low air pressure warning signal comes on, you should:
Explanation
If the low air pressure warning signal comes on while you are driving a vehicle with air brakes, you should immediately bring the vehicle to a safe stop while you are still able to control the brakes. Inspect and repair the brakes as soon as possible.
12. Vehicles equipped with Anti-Lock Braking Systems (ABS) have ____ malfunction lamps to indicate when the ABS is not working.
Explanation
