Abstract: Apparatus and method for leak testing and adding lubricating oil to enclosed reservoirs of undercarriage components of crawler-type equipment. Barometric pressure is measured by a transducer mounted on a handle from which an elongated wand extends, the wand having a nozzle on the end opposite the handle. The wand is inserted into the reservoir and communication is successively established and terminated between the handle and a source of pressurized nitrogen, a vacuum generator and a source of lubricating oil. After raising the pressure in the reservoir by connecting it to the nitrogen source, pressure is again measured at the end of a wait period to determine if the drop is greater or less than a predetermined amount indicating seal integrity.