I was looking at my master cylinder, and the rust below the bleeders where the brake fluid must have run a bit. I have the master cylinder off, the calipers off, proportioning valve off, will be changing the brake lines, and could pop in new rear cylinders if necessary. My question, as per the title, is should I go ahead and flush the various parts that are all off (or are coming off) anyway, and install DOT 5? I like the lack of water absorption and the fact that the silicone won't eat my paint. This sounds like a good deal for a car that will be detailed and only driven on nice days. However, I've read that the silicone can cause problems with natural rubber and the pedal can be a bit spongy as it compresses more that the glycol based fluids. Recommendations? Experiences?