The invention relates to an apparatus and method of statically sealing a reciprocating-type fuel pump, such as a direct injection high pressure piston-type fuel pump. The first embodiment of the invention is a fuel pump comprising a pump body, a fuel reservoir within the pump body, wherein the fuel reservoir is capable of holding fuel and a bellows attached to the pump body, wherein the bellows is a stretchable membrane acting as a static seal. The second embodiment further comprises a diaphragm seal inside the pump body, and adjacent to the fuel reservoir, and a working fluid reservoir adjacent to the diaphragm seal, wherein the working fluid reservoir is capable of holding fluid. The diaphragm seal is a static seal separating the working fluid reservoir and the fuel reservoir.