The invention relates to an automatic lubricating pump (1) for a machine having a hydraulically actuated percussion tool (4), such as a hydraulic hammer for example. The lubricating pump (1) is designed such that it can be connected to a pressure line (P) of the hydraulic circuit (2). The lubricating pump (1) has a drive piston (8), designed such that it can be driven by the hydraulic circuit, and a feed piston, connected to the drive piston in a motion-transmitting manner, of a feed pump (9), by means of which lubricant is fed to a lubricating point. The service life of the lubricating pump can be prolonged compared with conventional pumps if the drive piston (8) is designed to be double-acting with two drive chambers (8c, 8d) and a hydraulically operable changeover member (16) is provided which can be connected in the hydraulic circuit and by means of which the drive chambers (8c, 8d) can be alternately and automatically connected to the pressure line (8) during operation.