a high pressure plunger pump comprises a centrally arranged pressure valve , an oscillatingly movable plunger , a sleeve guided on the plunger and limiting a working chamber , a suction pump which surrounds the sleeve and accommodates an aspirated fluid , the sleeve having a ring chamber which opens towards the plunger , and a bush which is arranged in the ring chamber and supported against the plunger , the bush abutting against the plunger .