Abstract: A source fluid supply and pressure control system for hydraulic motors, comprising a motor control valve having valve instrumentalities to govern pressure at its inlet and at its motor ports, and to also limit the supply of source fluid to the inlet in accordance with demand.

Abstract: A spool type control valve mechanism for use with backhoes, front end loaders, and other apparatus having a number of hydraulic cylinder driven work performing members whose motions must be coordinated in order to produce a prescribed work operation. Pressure compensating valve means which provides for regulation of the rate of flow to the cylinders of pressure fluid from a common supply passage also functions automatically to control connection of the cylinders with the supply passage in accordance with the work load on the cylinders, at times when the valve spools of all the control valves are in their working positions.