Abstract: An hydraulic brake booster for an automobile hydraulic system comprising of a boost cylinder, a boost piston and a boost chamber defined by a boost piston working in a bore in a body and being adapted to apply an output force to an output rod in response to a pressure applied to a boost chamber under a control valve, in turn responsive to an input force from input rod, wherein the input rod move in a forward operating direction up to a prescribed point so as to prevent fluid from a radial high pressure supply port from entering the boost chamber when the booster is in an inoperative position, any added movement of the input rod in a forward operating direction lifts the boost piston ball and uncovers the supply port so as to allow pressurized fluid into the boost chamber from the accumulator.

Abstract: An hydraulic brake booster for an automobile hydraulic system comprising of a boost cylinder, a boost piston and a boost chamber defined by a boost piston working in a bore in a body and being adapted to apply an output force to an output rod in response to a pressure applied to a boost chamber under a control valve, in turn responsive to an input force from input rod, wherein the input rod move in a forward operating direction up to a prescribed point so as to prevent fluid from a radial high pressure supply port from entering the boost chamber when the booster is in an inoperative position, any added movement of the input rod in a forward operating direction lifts the boost piston ball and uncovers the supply port so as to allow pressurized fluid into the boost chamber from the accumulator.