A brake system for actuating a pair of front wheel brakes and a pair of rear wheel brakes is selectively operable during a manual push-through mode. A primary power transmission unit actuates at least one of wheel brakes in a normal braking mode. A secondary power transmission unit actuates the front wheel brakes in a backup braking mode. A primary electronic control unit controls at least one of the primary power transmission unit and a pair of rear brake motors. A secondary electronic control unit controls at least one of the secondary power transmission unit and the rear brake motors. An ABS modulator arrangement is hydraulically interposed between at least one of first and second three-way valves and at least a selected wheel brake. A multiplex control valve arrangement is hydraulically interposed between the secondary power transmission unit and the front wheel brakes.

The present disclosure in at least one embodiment provides a brake apparatus for vehicle, comprising: a reservoir configured to store brake oil; a pump housing configured to support the reservoir; a hydraulic circuit provided within the pump housing and connected to a wheel brake of the vehicle; a primary brake unit including a primary brake motor provided on a first side of the pump housing and configured to supply a first hydraulic pressure to the wheel brake via the hydraulic circuit; and a secondary brake unit including a secondary brake motor provided on a first side of the pump housing and configured to supply a second hydraulic pressure to the wheel brake via the hydraulic circuit.

A method is provided for operating a motor vehicle brake system that includes an actuatable brake master cylinder, a hydraulic brake booster, and at least one brake circuit that has at least one hydraulically actuatable wheel brake and at least one hydraulic-pressure generator driven by electric motor. The method includes monitoring a state of actuation of the brake master cylinder is monitored, and, upon detecting a maximum state of actuation, activating the hydraulic-pressure generator to increase the hydraulic pressure adjusted by the brake master cylinder in the brake circuit.

A power piston in a power cylinder borehole of a hydraulic block of a hydraulic power unit of a hydraulic power vehicle braking system is only guided radially in an axially delimited guide section. The power cylinder borehole is configured with a larger diameter axially outside the guide section. A brake fluid channel extends through the guide section up to an opening of a brake fluid line.

An electromechanical brake pressure generator for a hydraulic braking system of a vehicle, including a threaded drive system for converting a drive-side rotary motion into a translatory motion for brake pressure generation. The system includes a spindle rotatable via an electric motor, a spindle nut cooperating with a thread of the spindle so the spindle nut is axially displaceable with a rotation of the spindle and a brake fluid is loadable or relievable, and a housing which, together with the spindle nut, forms an anti-twist protection which secures the spindle nut against twisting during rotation of the spindle. The spindle nut forms at least one spindle nut reference surface, which cooperates with at least one stop surface, which is stationary with respect to the housing, in a relief end position of the spindle nut in such a way that an instantaneous axial position of the spindle nut is determinable therefrom.

A non-return valve having a valve opening spring is positioned between an unpressurized brake fluid reservoir and a brake master cylinder of a hydraulic vehicle power brake system having an externally-powered brake pressure generator. The non-return valve allows for a flow-through in the direction of the brake master cylinder and blocking against a return flow from the brake master cylinder into the brake fluid reservoir starting at a counterpressure in the brake master cylinder specified by the valve opening spring.

In a hydraulic brake system, when a main power supply is in an abnormal condition in which it cannot supply electric power to a pump motor, etc., the pump motor is operated with electric power supplied from an auxiliary power supply, irrespective of the presence of a braking request. Thus, when the main power supply is in the abnormal condition, the number of times inrush current flows is reduced. As a result, the voltage of the auxiliary power supply is less likely to be lower than an operation minimum voltage, and the hydraulic brake system is less likely to be unable to be operated.

A simulator valve includes a housing having a pedal simulator passage and a master cylinder passage extending therethrough. The master cylinder passage is located longitudinally between the first housing surface and the pedal simulator passage. An armature is located at least partially within the housing for selective longitudinally reciprocating motion with respect thereto between first and second armature positions. A poppet is located within the housing for selective longitudinally reciprocating motion with respect thereto between first and second poppet positions. The poppet defines a first valve and a second valve the poppet includes a poppet bore extending longitudinally therethrough and selectively occluded by the first valve. A damped flow fluid path selectively permits fluid communication therethrough from the master cylinder passage to the pedal simulator passage. A free flow fluid path selectively permits fluid communication therethrough from the pedal simulator passage to the master cylinder passage.

A method for checking functionality of a motor vehicle braking system. The braking system has a main module, including: hydraulically actuatable wheel brakes, pairs being assigned to respective brake circuits; at least one electrically actuatable wheel valve per wheel brake sets wheel-specific brake pressures; a pressure provision device actively builds up pressure in the wheel brakes; a pressure-medium reservoir at atmospheric pressure, and an auxiliary module, which has for each of two wheel brakes: a pressure sensor for measuring pressure in a wheel brake line; an open when deenergized isolating valve in the wheel brake line; a pump. At least one variable is measured to assess functionality of the braking system. Using least one acceptance criterion, and checked whether the variable satisfies the acceptance criterion. Determining at least one variable representing the viscosity of the brake fluid, and the at least one acceptance criterion depends on a variable representing viscosity.

A brake system, including four hydraulically actuatable wheel brakes. Each wheel brake is assigned in each case one outlet valve which is closed when electrically deenergized. Each wheel brake is assigned in each case one inlet valve which is open when electrically deenergized. The brake system furthermore includes a simulator which is actuatable by a brake pedal, wherein two pressure provision devices are provided for actively building up pressure in the wheel brakes, two brake circuits are hydraulically formed, wherein, in each brake circuit, in each case one pressure provision device is hydraulically connected to two wheel brakes, and wherein two separate on-board electrical systems are provided, and wherein each pressure provision device is fed in each case by one of the two on-board electrical systems.