Abstract: A high performance anti-lock brake system is suitable for both original equipment and after-market applications. The system comprises a conventional hydraulic link between a master cylinder and a wheel cylinder. A cut-off valve is provided to separate the hydraulic link into an upstream portion and a downstream portion. A one-way valve is provided in parallel relation to the cut-off valve to ensure the possibility of hydraulic communication from the wheel cylinder to the master cylinder at all times. Downstream of the valves, piezoelectric discs are provided within the hydraulic link. When a skid condition is sensed, for example, by monitoring a ratio between the rate of change of wheel deceleration and the rate of change of hydraulic force at the wheel cylinder, brake force control is initiated. A controller closes the cut-off valve and controls the voltage applied to the piezoelectric discs to contract the discs, thereby reducing the pressure in the wheel cylinder.