Thanks for the suggestions!
I know my fluid is good (installed speed bleeders a in spring and flushed er then) but the problem predated it. I kinda hoped the new fluid would swell the seals....
The P.O. didn't keep records so who knows if it was original. It sure was murky.
Don't know of anything that would vibrate/make noise on the master cyl unless it's the clutch lever.
I don't think its the lever because I can gently place my hand on the lever and the buzz does not change, (I tend to ride with my controls covered most of the time) but the sound disappears when I rest my hand on the reservoir cover .
It's not the miles it's the years old and type of miles; city miles are the worst due to frequent shifting and heat soak.
I do live
in Minneapolis and commute in traffic daily but I'm only responsible for the most recent 12000 miles and an shes an '02, so seems kinda soon.
And its the single drop of fluid that infrequently appears on the tank that makes me wonder about the piston/push-rod seal.
Has anyone else seen this drip?