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 answer choices. To pass, the applicant must answer at least 20 questions correctly. Test questions come from the Oklahoma 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
7. 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.
8. A low air pressure warning signal:
Explanation
Any vehicle with air brakes must be equipped with a low air pressure warning signal.
9. Why do large vehicles use air brakes?
Explanation
If used and maintained properly, air brakes are a safe and effective way to stop large, heavy vehicles.
10. To ensure normal stopping power, drivers of vehicles equipped with a front brake limiting valve should:
Explanation
Some older vehicles have front brake limiting valves with "normal" and "slippery" settings. Setting a brake limiting valve to "slippery" reduces the vehicle's stopping power, so a driver should make sure the valve is in its "normal" position. Front wheel braking has proven to be effective in all driving conditions.
11. When the spring brakes are on, you should never:
Explanation
Never push down the brake pedal while the spring brakes are activated. The combined force of springs and air pressure could damage the brakes.
12. What color malfunction lamps do vehicles equipped with ABS have?
Explanation
