What Is a Dual Brake System?
by Anne DavisMost vehicles equipped with air brakes use a dual brake system, also known as a dual air brake system. This system is safer because it allows for a secondary course of action in the event that the primary braking system fails.
Purpose
The purpose of a dual air brake system is to accommodate a mechanically secured parking brake that can be utilized during a service brake failure and to accommodate the need for a modulated braking system in case either or both systems fail.
Basic System
The dual air brake system is actually two brakes in one, giving the system a larger reserve capacity. On a two-axle vehicle, like a sedan, one circuit focuses on the front axle while the other operates the rear; if one circuit fails, the other is isolated and remains active, allowing the vehicle still to utilize its brakes.
Operation
When the brakes are applied, air is taken from the primary reservoir and delivered to the rear brakes; simultaneously, air is taken from the secondary reservoir and delivered to the front brakes. If a leak develops in either system, the other continues to operate independently, allowing the vehicle to retain its braking ability.
Writer Bio
Anne Davis writes pieces on domestic and international travel, automotive maintenance, education and health. She graduated with a Bachelor of Arts in English and history, and is pursuing graduate study in a related field.