Abstract: A brake system includes a series of rotors for operatively coupling to a shaft and stators for operatively coupling to a frame. A service brake system includes a singular annular service piston extending continuously around the series of rotors and stators and a parking brake system includes a singular annular parking piston positioned to extend continuously around the series of rotors and stators. The service piston nests with the parking piston, under a spring bias, such that the parking piston and service piston continuously engage together around the series of rotors and stators to thereby create the parking brake forces. Springs act on the parking piston to drive the parking piston and nested service piston to engage for parking brake forces. Pressurization of the parking piston deactuates the nested pistons. Then separate pressurization of fluid acts on the service piston to overcome the spring bias and separate the service piston from the parking piston to create service brake forces.

Abstract: A brake system includes a series of rotors for operatively coupling to a shaft and stators for operatively coupling to a frame. A service brake system includes a singular annular service piston extending continuously around the series of rotors and stators and a parking brake system includes a singular annular parking piston positioned to extend continuously around the series of rotors and stators. The service piston nests with the parking piston, under a spring bias, such that the parking piston and service piston continuously engage together around the series of rotors and stators to thereby create the parking brake forces. Springs act on the parking piston to drive the parking piston and nested service piston to engage for parking brake forces. Pressurization of the parking piston deactuates the nested pistons. Then separate pressurization of fluid acts on the service piston to overcome the spring bias and separate the service piston from the parking piston to create service brake forces.