Hi Phil,
Good point. No, my cylinders are all new replacements. There is nothing of significant vintage or refurbished.
One of the sources I read (may even be the one I had supplied link to) talks about how persistent minor leaks actually slowed to stop, with use of silicone DOT 5 fluid. I think that could be taken a number of ways. One, fluid may be slightly higher viscosity, not able to leak out. Or two, the fluid caused some swelling to a flexible component such as a cylinder boot. That would be a worry, however I don't recall the event stated in a negative context.
