Synthetic Brake Fluid?

[Chopper]

Here's a good answer... brake fluid attracts and holds water, any time it is exposed to air, it will absorb water. Water is bad for many components,ie. steel brake lines, ABS pumps and so on. This is why it should be changed out every 2 years. Synth brake fluid doesn't attract water, but it doesn't hold up well to heat caused by severe braking (like at a racetrack or maybe in mou ntains) this is why it is banned at every track I know of. For a daily driver, it is a good choice, as it will not reflect neglect as quickly, and you ain't heating up your brakes that much on the way to work...well most of you As for brands, I doubt there is much of a difference between major name brands. You should probably avoid Joes' super synthetic, go with Valvolene or something.

[Zorak]

Actually, it's silicone (not synthetic) brake fluid that does not attract water. The brake fluid that is labeled "synthetic" is still glycol-based; the "synthetic" label is more of a marketing tool than anything else. The manufacturers claim that because the glycols are not naturally occurring molecules, they are "synthetic".

As far as silicone brake fluid goes, you probably want to stay away from it, for several reasons, but the biggest one is that if your power brake vacuum booster is leaking, any silicone brake fluid that gets sucked into the engine will burn into silica (sand) which, as you can imagine, is not a good thing for internal engine parts. Glycol burns off harmlessly. Silicone will also cause a "spongy" brake pedal. Silicone's advantages are that it will not absorb water and won't eat your paint if you spill it. But for later model vehicles you are better sticking with a glycol based fluid.