Joey,
Having lived through many servo failures with the "disappearing fluid"
syndrome, I think I have found the guilty party.
The hydraulic fluid is separated from the vacuum actuation source (big
cylinder) by a seal around the shaft from the hydraulics to the piston.
This seal is the last one inside the aluminum hydraulics, not the large
canister piston seal.
This is a weak point in the design, and often fails by ordinary use
wear. Fluid is then drawn from the hydraulic pressurized system by
being "sucked" into the canister through the leaky shaft seal. From
their it goes past the large piston seal, then through the vacuum lines
to the intake manifold, and out the exhaust.
No external indications are visible, with the exception of the loss of
fluid in the reservoir. The leak is not severe enough to cause cloudy
exhaust, though. The inside of the rubber connecting hose will, however,
show fluid signs in a vacuum only system. An easy check.
Make sure your seal hydraulic outer housing, in the aluminum servo, and
the portion of the shaft that slides in this "last vacuum seal" is in
good shape with no scores, and that the replacement seal is of good
quality.
You should abide by the recommendations to stick with Castrol GT/LMA (no
relationship to Ford GT! :-) ) brake fluid as it is a good quality DOT
4 high temp fluid, reasonably priced, available at most foreign parts
stores and some quality auto parts stores.
There is a rationale about seal swelling to seat the hydraulic rubber
seals in all the hydraulics, and silicone DOT 5 won't do this, which may
be correct. There is a counter argument that one should swell the new
seals first with Castrol, then purge it all out for DOT 5 silicone.
At first glance this looks reasonable, and not inexpensive, but the
silicone fluid will not absorb and water that can get trapped in the
system, so a flush with Castrol is recommended. Sounds like it is
getting labor intensive and expensive, when DOT 4 is probably as good a
temperature capability as one would normally need.
Bottom line, it works well, and at high temperature. Still has the same
moisture absorbent issues as all other normal brake fluids, so should be
flushed with new fluid through all the lines every couple of years, as
recommended. When the brake reservoir is discolored with a dark color
(rubber seal pieces?) is a good indication that a fluid change is
needed, or that you have a seal breaking up.
Good luck,
Steve
___
Steve Laifman
Editor - TigersUnited.com
Caseyh4312@aol.com wrote:
>ok thanks Ron.
>
>I will do that. And yes i am glad this rebuild kit came with instructions.
>
>Also, why isnt there any other people responding? Is it just because I asked
>the question? Or is it cuz they are to caught up fighting about this GT40
>thing?
>
>I did read through the archives and there is nothing on tip or any other
>things. Its just about what is wrong when i dont have any leaks and i am
>loosing brake fluid. Thats pretty much all that is in there.
>
>Thanks again,
>Joey Hiykel
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