Stupid brake fluid question, DOT5, Silicone fluid

[Gotlabs]

Does anyone use DOT 5 silicone based fluid? I've read mixed reviews..what's the good word TT?

[MELK-MAN]

just use DOT 4 like the manual and the top of your master cylinder says to do ? .. can to a search for it, but that stuff just isn't worth the hassle in a motorcycle. DOT4 will work just fine..

[Gotlabs]

Too late for that..vaccuum bled and using DOT5 now. Curious to see if any has any complaints other than the long process of getting it all out of the system.

[FRECNDY]

In general, the molecules in silicone DOT5 are bigger and have more space between them, so it's slightly more compressible than DOT3 and 4. Especially when it gets hot, the feel just isn't as firm.

The other problem is that it doesn't absorb water, so (although this is more likely on a car) if moisture does make its way into the system, instead of being completely removed by a full flush, you can still have pockets of water that stay trapped and sit there rusting the system from the inside out.

I go with Motul RBF600 for performance stuff on pavement. Not riding fast enough on dirt to need it yet. ATE Typ200 or Super Blue are better value, and will work just as well for most people.

Unfortunately, it's getting really hard to find decent brake fluid at an auto parts store anymore.

[Gotlabs]

Well, it looks like I'm going back to DOT4. I've done a little more research and have read in a few places that DOT5 silicone fluid IS NOT recommended for Brembo brake systems due to incompatibility with natural rubber. So much for the bike being prepped for a 0500 departure tomorrow morning.

[bulldog1331]

Use DOT 5.1 or 4...you are correct about 5 not being that compatible with rubber.