Mark Stahlke wrote:
>Checking the fluids in my '71 TR6 this morning, I noticed a peculiar
>contaminant in my DOT 3 brake fluid.
>It is very dark gray and forms fluffy looking clumps. It appears to be fine
>particulate rather than liquid. There is quite a bit of it in the fluid
>reservoir. The brake fluid itself has an amber color.
Mark:
This sounds suspiciously like the gunk that accumulates in the CLUTCH
master cylinder on my '73 TR6. There was a time when it was necessary for
me to rebuild the master and slave in three week intervals, believe it or
not. Now it is not required nearly that often, and in fact since putting
the car back on the road after a 6 year slumber in April this year, I have
not had to rebuild the cylinders. I HAVE, however, disassembled and
cleaned them to rid the system of that gunk, (and it's about time I do that
again, too) but despite the rapid build up of this gunk, (fluid is almost
completely opaque in just a week or more) the hydraulics continue to
function quite well, it would seem.
I have consulted the list on this a couple times, and the best suggestions
I got were to have the cylinders sleeved with brass... White Post
Restorations does this... and this apparently renders any hydraulic
cylinder bulletproof. I do intend to have this done.
Do you know if the cylinder was honed when it was rebuilt? Some
suggestions I got involved polishing the bore. The theory being that a
honed cylinder is a bit too abrasive on the seals. I think that this is on
the right track... however, in my case, this gunk would accumulate even
with a BRAND NEW cylinder! It cannot be the brake hoses if we're talking
about the same gunk, (and I'm conviced we are) as there are no rubber hoses
in the TR6 clutch hydraulics. Only that orange nylon flex hose, and yet
the grey gunk still appears. It may be a good idea to replace the rubber
hoses in your brake system, but I'll bet my last dollar it will not affect
this gunk.
Incidentally, I have absolutely no problems with my brake master in this
regard. Fluid stays perfectly clear. Also, back when I was rebuilding
clutch hydraulics every three weeks, I tried silicone brake fluid and got
the same gunky results!! VERY frustrating!
Good luck,
Pete Chadwell
1973 TR6 CF10732
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