Swift L4-1298cc 1.3L SOHC MFI (1997)
As the discharge rate of the P/S pump increases in proportion to the pump revolution speed, a flow control valve is added to control it so that the
optimum amount of fluid for steering operation is supplied according to the engine speed (driving condition).
Described below is its operation at different engine speed.
When Idling
The fluid discharged from the pump is supplied through the clearance around the rod in orifice A1 to the gear box.
When Running at Low Speed
As the engine speed rises, the pump discharge rate increases and causes a pressure difference to occur between both ends of the orifice
(P1-P2). Thus the pressure exceeding the flow control spring force pushes the flow control valve to the right as shown in the image, making the
opening in the orifice narrower through which only a necessary amount of fluid is fed to the gear box and the excess fluid is returned to the
pump.
When Running at High Speed
As the engine speed rises higher, opening in the orifice is made narrower and fluid flow to the gear box reduces. As a result, hydraulic pressure
application is slow at the start of the steering wheel turn. This provides straight-ahead stability to suit the driving condition with the steering
wheel operated near its neutral position.
