Abstract: An adjustable hydraulic shock absorber of the dashpot type which includes an elongated outer tube and an inner tube fixed in said outer tube. A piston is movably mounted in the inner tube and has a piston rod extended outwardly of the outer tube for receiving reciprocating actuating loads. A double action, flexible, tubular diaphragm is positioned in the outer tube, with its inner end secured to the outer tube in a position surrounding one end of the inner tube, and with its outer end secured to the piston rod, so as to form an expandable fluid reservoir. The reservoir is connected by passageway means to the inner tube. The reservoir, passageway means and inner tube are normally filled with fluid under pressure so as to normally move the piston to an initial load receiving position.