Abstract: A lubricating device in a pneumatic tool or the like, which device is tool mounted beyond an on-off or throttle valve and utilizes air pressure from within the tool to achieve a metering flow of stored lubricant. The device is installed for convenient servicing and includes a lubricant storage tank, a lubricant outlet, a wick means and an intermediate "ready" chamber. The latter receives lubricant from the storage tank and is pressurized in an open position of the throttle valve to induce a movement of lubricant through the wick means for exposure to flowing pressure fluid. Valving means are operative to control access of air from the ready chamber to the storage tank.