900 SE Convertible V6-2489cc 2.5L DOHC EFI (1997)
Power Steering Pressure Control Valve: Description and Operation
CONTROL OF PRESSURE AND FLOW
The function of the control valve is to regulate the flow from the pump so that it remains constant, regardless of engine/pump rpm.
One side of the control valve is in direct communication with the delivery side of the pump (A). The pump outlet (B) incorporates a restriction from
which a connecting passage (1) leads to the other side of the valve, which is fitted with a spring (2). In the rest position, the valve is pressed against the
outlet side.
Inside the control valve is an overflow valve (a) which, when the pressure exceeds a certain limit, is actuated by the pressure on the spring loaded side
of the control valve.
For the control valve to operate, a certain amount of fluid must circulate continuously through it, although not when the steering wheel is at full lock.
The pump delivers a maximum pressure of about 90 bar and a maximum flow of about 6.0 liters per minute.