This simplex replacement for positive displacement grinders readily adapts as a replacement for existing progressing cavity grinder pump systems with easy “drop-in” replacement. This replacement assembly includes a quick-disconnect coupling, a 20′ electrical cords with quick disconnect receptacle fitting, an adjustable gooseneck 1-1/4” NPT discharge pipe, a pump control and high water alarm switch. It is equipped with a 1 HP, 60 Hz, 1750 RPM, 230 Volts, 1 phase oil-filled – hermetically sealed motor with Class B winding with upper and lower ball bearing design. Protection is provided by a carbon/ceramic mechanical seal, Viton gaskets and square sealing rings as well as an integral thermal overload switch with automatic reset. The motor is encased in a machined, finned, Class 30 cast iron housing finished with a corrosion resistant baked powder coated epoxy finish. The high quality “working end” consists of a stainless steel hydraulic pump rotor and a hardened stainless steel cutter and disc manufactured to a Rockwell C55-60 standard. To complete this replacement system you will find that it is equipped with a pressure relief valve, check valve and an anti-siphon device.