A shock absorber includes a tube and a piston rod carrying a piston. The piston is configured for reciprocal movement within the tube. A floating piston, or other type of accumulator, is configured to move to accommodate fluid displaced due to successive portions of the piston rod entering the tube during compression of the shock absorber. The shock absorber includes a valve mechanism that utilizes the movement of the floating piston to move the valve between a first and second position, which preferably are open and closed positions.