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 four answer choices. To pass, the applicant must answer at least 20 questions correctly. Test questions come from the North Dakota Commercial Driver Guide. 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. The ____ tells a driver how much pressure is in the air tanks.
Explanation
A vehicle that is equipped with air brakes must also be equipped with a supply pressure gauge. This gauge tells the driver how much air pressure is in each of the vehicle's air tanks.
8. Air tank drains:
Explanation
In an air brake system, the air storage tanks are equipped with drains to allow water and compressor oil to be removed. The water and oil can damage the brakes if left to accumulate in the system.
9. How is the parking brake released?
Explanation
In newer vehicles with air brakes, the parking brakes are controlled by a diamond-shaped yellow knob. Pull the knob out to activate the parking brakes and push it in to release them.
10. Most heavy-duty vehicles use ____ air brake systems.
Explanation
The majority of heavy-duty vehicles are equipped with dual air brake systems.
11. If the brake pads rub against the brake drums and create too much heat:
Explanation
Brakes heat up with use. If they are overused and become too hot, expansion and chemical changes will make them less effective and eventually cause them to stop working altogether. This is known as "brake fade."
12. What color are ABS malfunction lamps?
Explanation
