APPARATUS AND METHOD FOR CONTROL OF A HYDRAULIC BRAKE SYSTEM INCLUDING MANUAL PUSHTHROUGH

A brake system includes a reservoir and a master cylinder operable to provide a brake signal responsive to actuation of a brake pedal connected thereto. The master cylinder is selectively operable to generate brake actuating pressure at an output for hydraulically actuating a pair of hydraulically actuated wheel brakes in a manual push-through operation. A power transmission unit is configured to selectively generate pressurized hydraulic fluid for actuating the pair of hydraulically actuated wheel brakes. First and second two-position three-way valves are hydraulically connected to respective ones of the pair of hydraulically operated brakes and to both the master cylinder and the power transmission unit. The first and second three-way valves each are configured to selectively switch the respective hydraulically operated brake to receive fluid from a selected one of the master cylinder, in a backup braking mode, and the power transmission unit, in a normal non-failure braking mode.