Posted by Mike Frank on October 01, 1997 at 22:43:43:
In Reply to: Silicone Brake Fluid? posted by Joe Mulinix on September 30, 1997 at 22:29:41:
Traditional brake fluids are hygroscopic, meaning that they absorb water like a sponge. Even if your system is tight as a drum, your fluid will gradually deteriorate by absorption of atmoshperic moisture. Eventually, it fails, usually when under stress.
Silicone fluid will not mix with water. At first blush, that sounds like an improvement. But if water gets into your system thru leakage or condensation, it forms a water 'bubble' in the silicone fluid. Wherever this bubble forms will be subject to rust. And the water will boil under stress, causing catastrophic brake failure. And silicone fluids may not react well with older rubber seals.
So that's the choice: a fluid which begins to degrade as soon as you open the can, or a fluid which doesn't degrade, but is prone to various sorts of sudden failure.