Abstract: A pump having a pair of intermeshing gear members retained in first and second bushings located in a cavity for pressuring a fluid from an entrance pressure to a desired exit pressure. The first bushing has a passage located therein which communicates a selected pressure less than the exit pressure which acts on an outer face of the first bushing to develop a clamping force which urges an inner face on the first bushing into engagement with the intermeshing gear members and the intermeshing gear member into engagement with an inner face on said second bushing to seal the entrance chamber from the exit chamber.