This document provides a service manual for tractor models T8010 through T8050. It describes the primary hydraulic power system, including the three hydraulic pumps that are driven by the transmission. A pressure and flow compensating piston pump supplies hydraulic flow to priority valves and then to steering, remote valves, and the three point hitch. A dual gear pump has front and rear sections, with the front supplying regulated pressure and the rear providing charge flow to the piston pump. An optional high flow piston pump is also described that provides increased hydraulic flow.