Join Date: Oct 2011
Location: Naval Diving and Salvage Training Center, Panama City, Florida, USA
Model: GL 1500 SE
I do not profess to be an "expert" mechanic by any stretch of our imaginations.
That said, I did have a fork seal leaking oil, one side, and oil was on the upper tube and running down on the front fender, etc.
Pushing down on the forks with the front brake held recreated the oil situation.
In researching my problem I found a motorcross mechanic who keeps the rubber bushings, the ones on the top of the lower forks, clean by doing a bit of preventive maintenance. Motor Cross, Gold Wing, debris can still build up and affect the fork seal.
So, he slides a 1.5 inch wide piece of plastic milk carton, with a small "J" shaped hook in the end, between the rubber seal and the fork. You slide it in about 3 inches or so, you get a feel for depth, sweep the perimeter of the tube, and the "hook" at the end brings up any debris. I did about 3 or 4 OCD passes. And there was junk under there, bad looking, gritty, nefarious junk.
This may not fix your current situation. It did work for me and I have not had any more leaks around that particular fork or the other one.