The master cylinder has been on there for nearly 30 years. I changed the fluid several weeks earlier before I noticed the drip. I washed it to make sure and the leak returned so it wasn't spilled fluid. It seems to be leaking at the joint btwn the master cylinder and the hand grip assembly. I have a new replacement MC unit but I don't want to waste it. Is there a gasket in the joint? I used BMW DOT 4 fluid. The brake works fine. After a week sitting there was a table spoon worth of fluid leaked (painted parts are all protected w/ plastic sheet). Any suggestions what to do now?