Abstract: An anti-lock braking system which incorporates a pressure modulator disposed between a master cylinder and one or more wheel cylinders of the vehicle. The pressure modulator includes an electrically operated pump for pumping fluid from the rear cylinders back to the master cylinder and a pressure responsive isolating valve for isolating the wheel cylinders from the master cylinder in response to operation of the pump. The system is particularly well suited for application to the rear wheels of the vehicle.

Abstract: An anti-skid control system for motor vehicles is provided wherein the higher one of the lefthand and righthand rear wheels is selected as a first computed speed; the lower one of the above two wheel speeds is selected as a second computed speed; the lower one of the first computed speed and lefthand front wheel speed is selected as a third computed speed; the lower one of the first computed speed and righthand front wheel speed is selected as a fourth computed speed; and a reference speed is set up on the basis of the first computed speed in such a manner that it is lower than the first computed speed by a predetermined amount and follows the first computed speed with such a speed difference.

Abstract: A hydraulic braking system having an antiskid function and a holding function for keeping the vehicle immobile during vehicle stoppage is further provided with a malfunction alarm function wherein the components of the braking system are checked each time the holding function is performed and the operator is provided, directly or indirectly, with a warning in the event there is failure or malfunction of the components.