Operation

A rotary-type valve body is used to control the hydraulic steering assist. Fluid under pressure is directed to the gear housing and into the valve body. The valve body then directs fluid to the power cylinder.
A spool valve, connected to the stub shaft by a locating pin, rotates within the valve body. Fluid directional passages, machined into the spool valve, are aligned with fluid passages in the valve body as the spool valve rotates. Fluid is directed through these passages, into either side of the power cylinder through the externally mounted oil lines.