Abstract: A tool for disassembling hydraulic valve lifters of the type having a housing enclosing a plunger longitudinally movable through a cylindrical cavity therein, the plunger having a coaxial cavity therein with a circumferential lip or groove adjacent the open end thereof. A shaft communicates into the coaxial cavity of the plunger. The shaft has at the distended end thereof an annular head for engaging the circumferential lip adjacent the open end of the plunger. The distended end of the shaft and the annular head also include a longitudinal slot therethrough parallel to the axis of the shaft. An activating device is included adjacent to the longitudinal slot for enlarging the annular head to engage the circumferential lip inside the plunger. The tool also includes a frame for communicating with and restraining the longitudinal movement of the housing.