Fluid pressure accumulator, in particular for a hydraulic brake system of a vehicle, and method of assembling said accumulator

A pressurising agent storage unit, esp for a vehicle hydraulic brake unit, comprises a compression agent chamber, with an outer housing and a piston, and a sealing element which seals the chamber between the housing and the piston. The housing has an opening for supplying the compression agent, and the opening (15) is connected to the compression agent chamber during storage unit (10) assembly and before the piston (13) is placed in it operating position. Two sealing elements are located between the housing and the piston, and the second sealing element is in contact with a PTFE supporting element.