Abstract: A method and apparatus for controlling brakes using a reciprocating cut valve actuated by an expander piston that is moved via a crank pin on a crank shaft. The cut valve cuts off caliper pressure and adjusts the volume and pressure of an output hydraulic chamber to effectuate antilock braking. When changing from antilock braking to normal braking, the movement of the expander piston is controlled by repeatedly changing a crank angle of the crank pin during specified time intervals. The rate of increase in caliper pressure can be set according to (1) detected brake operation which is detected from a present crank angle and a target crank angle and (2) the frictional state of the road surface which is estimated from vehicle acceleration/deceleration.