Rotary Valve

The "rotary valve" is the key to the operation of power steering. It directs the power steering fluid under pressure to either side of the rack piston, which converts hydraulic power to mechanical force. Friction from the wheel causes a torsion bar in the rotary valve to deflect. This changes the position of the valve spool and sleeve, directing fluid under pressure to the proper end of the power cylinder. The difference in pressure on either side of the piston (which is attached to the rack) helps move the rack to reduce turning effort. Find out how to clean your valve