Abstract: Master cylinder pressure of either or both of the primary and secondary braking circuits is sensed by a pressure sensor or sensors mounted in a manifold which is installed directly on a brake pressure modulator housing when the modulator is manufactured. The pressure sensors receive power and are grounded through the electronic control unit which is an integral component of the modulator; accordingly, the sensors do not require external electrical connections other than those already provided on the modulator. Since the sensing manifold is installed and tested for leaks when the modulator is manufactured and before the modulator is shipped to the vehicle assembly plant, assembly operations in addition to those required in installation of the modulator in the vehicle braking system are not required.

Abstract: Master cylinder pressure of either or both of the primary and secondary braking circuits is sensed by a pressure sensor or sensors mounted in a manifold which is installed directly on a brake pressure modulator housing when the modulator is manufactured. The pressure sensors receive power and are grounded through the electronic control unit which is an integral component of the modulator; accordingly, the sensors do not require external electrical connections other than those already provided on the modulator. Since the sensing manifold is installed and tested for leaks when the modulator is manufactured and before the modulator is shipped to the vehicle assembly plant, assembly operations in addition to those required in installation of the modulator in the vehicle braking system are not required.

Abstract: A brake booster provides additional boost capacity without unduly increasing booster size and weight by providing a vacuum pump connected so as to add its additional vacuum capacity to that of the normal vacuum source when activated in response to sensed approaching run-out. The additional vacuum is provided by connecting the vacuum pump in a second conduit between the vacuum source and the booster vacuum chamber in parallel with a first conduit connecting the vacuum source directly with the booster vacuum chamber, with check valve means in the first and second conduits preventing substantial vacuum loss from the vacuum chamber.