What about DOT 5.1? Not silicone based and is supposed to be compatible with DOT 3 & 4.
I guess it all boils down to ...why?
The sytem was designed for dot4
DOT4 fluid is cheap, and available everywhere...
DOT 4 is what you have in your complete brakensystem currently... why do DOTx just for clutch...?
Clutch never sees the temperatures brake fluid does, therefore the "benefit" of high temp reduction of chanced boiling, is lost...
A little reading, in simple terms..
http://www.stoptech.com/technical-support/technical-white-papers/brake-fluidThe one thing I find interesting, and have know as a trait of silicone oils, even tho they do not absorb water, its a tradoff as they are highly compressable compared to glycol, glycol/borate fluid.. innessence, this means you need to compress them
more, as in more volumn, and pressure, to get the same mechanical output and resultant pressure, say on a piston, as the glycol based fluids.
Pay$$$ for something that really has no benefit, and as a fluid, should be changed periodically anyways, no matter which is used, is a choice you have to make.
Seeing as the clutch system gets actuated 10x or more times as much as the brakes do, and there is more contamination because of this, it only makes sense, to me anyways, to keep it simple and cost effective, while still maintaining OEM spec.
YMMV
