A hydraulic pressure control system for a split brake system including a tandem master cylinder, first and second wheel brakes, a first braking line between one of the tandem master cylinder and the first wheel brake, a second braking line between the other of the tandem master cylinders and the second wheel brake, an anti-skid actuator positioned within the first braking line to thereby decrease and increase brake fluid pressure transmitted to the first wheel brake in response to rotational conditions of the wheels, and a control valve assembly communicating with the first braking line between the anti-skid actuator and the first wheel brake at a first side thereof, and communicating with the second braking line at a second side thereof, the control valve assembly including a normally open valve member interrupting the second braking line when fluid pressure within the first braking line attains a predetermined value, and balance piston means being balanced by means of fluid pressure transmitted to the first and second wheel brakes, respectively, to thereby maintain the fluid pressures of the first and second wheel brakes at the same magnitude.