A brake system for actuating at least one wheel brake 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 during a manual push-through mode to generate brake actuating pressure to at least one output for hydraulically actuating at least one wheel brake. A power transmission unit is configured for actuating at least one of the wheel brakes in a non-failure normal braking mode. A secondary braking module is configured for selectively providing hydraulic fluid to each of the wheel brakes in an enhanced braking mode. The secondary braking module includes a pump motor driving at least one pump unit. Each pump unit is operatively connected to a fluid accumulator associated with the correlated wheel brake for selectively varying an amount of hydraulic fluid provided to the wheel brake.