Samson 039-340520 Pumpmaster 4 3:1 16 gal Pump

The Samson 340520 Pumpmaster 4 is a double-acting, air-operated oil pump engineered for medium-sized workshops, service bays, and maintenance facilities. With a 3:1 pressure ratio, it multiplies compressed air input to deliver a steady, medium-pressure flow of lubricants, making it effective for dispensing motor oil, gear lube, hydraulic oil, and transmission fluid. The double-acting design means the pump moves fluid on both the upstroke and downstroke, resulting in smoother, more consistent output with less pulsation than single-acting alternatives.

Installation is straightforward thanks to the bung-mount configuration. The included bung adaptor threads directly into the standard opening on a 16-gallon drum, securing the pump in place without the need for additional brackets or stands. This makes drum changes relatively quick when stock needs to be rotated. Because the pump runs entirely on compressed air, there are no electrical components at the point of use, reducing ignition risk in environments where flammable fluids may be present. The Pumpmaster 4 is a practical mid-range solution for shops that need reliable fluid transfer without the higher output and cost of larger ratio pumps.