General Description

POWER STEERING SPEED SENSOR
The power steering speed sensor is a trochoid-rotor, hydraulic pump combined with a relief valve and a one-way valve. It is driven by the speedometer gear shaft which in turn is driven by a helical gear on the differential. The power steering speed sensor turns only when the car is moving, controlling the assist control valve.








ONE-WAY VALVE (IN POWER STEERING SPEED SENSOR)
When the vehicle is moving at high speed, negative pressure develops at the sensor inlet because the power steering speed sensor is pumping faster than the fluid can be supplied. To compensate for this, the outlet and inlet ports are connected internally by a passage containing a one-way valve that lets output fluid recirculate to the inlet port to equalize pressure.








RELIEF VALVE (IN POWER STEERING SPEED SENSOR)
When the vehicle is moving in reverse, the power steering speed sensor also turns backward and pumps fluid in the opposite direction. To avoid building up pressure in the reaction chambers that would increase steering effort while driving in reverse, the inlet and outlet-ports are connected by a second internal passage containing a relief valve that allows the fluid to recirculate.