Teves & Bosch ASC/5

The inlet and outlet solenoids in the hydraulic unit are regulated by the control module to provide the - Pressure Build, Pressure Hold and Pressure Drop cycles needed to pulse the rear brakes.

The return pump in the hydraulic unit supplies the volume of brake fluid needed to apply the brakes.

The changeover valve is used to isolate the rear brake circuits so that ASC regulation at the rear does not effect the front brakes.

The Intake (or suction) valve is hydraulically controlled. It is held open by a spring to supply the hydraulic unit's return pump with brake fluid during ASC regulation.

The valve is closed by hydraulic pressure when the brake pedal is depressed.






Pressure Build
The inlet valves are open and the outlet valves are closed in pressure build.

Brake pressure is supplied by the return pump to the brake calipers for the pressure build phase of regulation.






Pressure Hold
During pressure hold, the inlet valves are powered closed. The outlet valves remain closed and pressure is held in the brake calipers.






Pressure Drop
The outlet valves are powered open during pressure drop and the inlet valves remain powered closed.

The brake fluid is pumped through the inlet valve circuit for continued regulation If regulation is complete the brake fluid is returned through the open changeover valve in the hydraulic unit and the central valve in the master cylinder.