When changing the fork oil in a Harley-Davidson, it is advisable to use Harley-Davidson oil or an equivalent. This procedure works on all but ’02 through ’06 models with a cartridge on the left side. These were only found on the Hogs. Replacing the oil by drawing it into the drain hole on the bottom of the fork eliminates the necessity of removing all the fairings or anything covering the upper fork nut.
1. Raise the cycle so that the front forks are fully extended. Remove the upper Schraeder valve stem on top of the fork using the Schraeder valve removal tool.
2. Take the drain plug out located on the lower end of the fork tube using a wrench. Allow all the oil to drain from the tube. Insert the adapter plug into the drain hole and attach the hose.
3. Connect the vacuum source to the Schraeder valve on top of the fork tube. Insert the hose that is attached to the drain plug in the bottle of oil. Apply the vacuum to draw the oil into the tube. Continue to apply a vacuum to keep the oil from draining out of the drain plug adapter.
4. Remove the adapter plug and install the original drain plug. Remove the vacuum source from the top Schraeder and install the Schraeder valve core.