Abstract: A method for making a hydropneumatic accumulator with a replaceable bladder for an active vehicle suspension comprising the steps chemically treating a resilient single layer bladder with a gas to provide imperviousness of a compressible gas through the bladder, bonding a spherical bumper to a closed end of the bladder, engaging an inward facing seal portion extending around an "open mouth" portion of the bladder with an external groove extending around a cylindrical cap to close off the "open mouth" portion, slideably mounting the cap and said bladder in the interior of an accumulator housing to divide the housing into a first sealed chamber for a hydraulic liquid and a second sealed chamber for a compressible gas; and engaging a detachable ring with a groove in the interior of the accumulator housing to retain the cover and the bladder in the housing.