Switch to silicon brake fluid?

[PeteVS]

One thing to consider is the master cylinder gasket. My '63 Chevy has a flat, thick rubber gasket. There's a small hole in it that allows air to go into the chamber each time the brakes are applied or if there's a loss of fluid from a leak in the system. Each time a bit of fresh air comes into the reservoir, it brings a bit of moisture along with it. I'm not sure when it happened but shortly after '63, that flat gasket with a hole was replaced with a convoluted molded gasket, kind of like a bellows which would flex when the brakes were applied without the introduction of moist air to the the fluid itself eliminating the build up of water in the system, eliminating water collecting in the bottoms of master and wheel cylinders. When I redid the '63, I opted for silicone fluid instead of switching to a later master cylinder design.