I don't think I did a very good job of explaining myself. I had posted the
following in response to the comment below it:
> FWIW, I have had this exact same problem pop up when I
> recently switched to
> DOT5 silicone fluif. I've torn down the MC twice, and
> confirmed that it works as I think it should on the bench,
> and pulled the guts out of the residual pressure valve. The
> problem is reduced, but still there.
>
> I'm now convinced that this is the result of different fluif
> properties, as was suggested by another lister. Odd that
> this doesn't show up on all of the web pages discussing the
> pros and cons of DOT5.
The problem I was referring to was not "knock back" but the fact that the
M/C seems to hang up part way back after applying the brakes. The front
brakes remain partially engaged (drag). Tapping the brake pedal releases
it, and it springs fully back the last fraction of an inch. Like I tried to
say, I've disassembled the M/C twice, and the piston/spring assembly returns
quickly and completely when pushed in on the bench. I can't get it to
replicate the hang-up with it out of the car. The only thing that even
begins to make sense to me is that somehow with DOT5 fluid filling the
system, there is some sort of binding between the piston and cylinder walls.
Dean Mericas
Ann Arbor, MI
1965 TR4
1974 2000 GTV
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