Hydraulically actuated diaphragm pumps from Jaeco Fluid Systems Inc., of Exton, Pa., feature separate chambers for hydraulic fluid and gear lubricant. The chambers make it possible to use the best medium for hydraulic diaphragm pulsing and gear lubrication resulting in better pump performance and longer pump life. Specially designed for accurate, completely leak-proof metering of difficult-to-handle liquids, the pumps have a patented, heavy duty, totally immersed in oil, gear reducer system for superior performance.