Any time you have two metal surfaces moving in close quarters with each other as you do in a hydraulic jack, there will be friction. Where there's friction, there must be a lubricant to provide a thin, slippery wall of separation between the two metal surfaces. While the hydraulic fluid provides all of the lubrication needed by the hydraulic system, only grease can provide the lubrication necessary for the parts of the jack that aren't part of the jacks' hydraulics. Instructions 1, Locate the grease nipple on the jack. The owner's manual for the jack will provide the location of the nipple. 2, Fit the grease gun fitting--located on the end of the hose that extends outward from the grease gun--over the grease nipple. 3, Pump the handle on the grease gun until grease oozes from around the grease gun fitting. 4, Remove the grease gun fitting from the jack's nipple. 5, Raise and lower the jack several times to distribute the grease.
Source:
