> I strongly recommend AGAINST silicon fluid. The biggest problem is that
> the systems in our LBCs are designed to have some amount of seal swelling,
I believe this to be worse than the arguements against DOT 3. I've used
silicone successfully for many years not, with no ill effects. For a street, or
seldom used car, it has several advantages:
-Does Not remove paint!
-Higher boiling point
-less hydroscopic (absorbs less water)
-Manufacturer suggested change interval much longer. (2-5 years)
Drawbacks-
-entrains air, which can make it more compressable. Not reccommended
for race and appliactions
-Should be used with a clean system, like when rebuilding w/new seals, to
avoid incompatiblies with other fluid types.
DOT 3/4 should be changed, more often, 1-2 years for street cars, as the
absorbed water reduces the boiling point, and leads to corrosion. The "wet"
ratings below are what happens after the fluid absorbs water from the air.
Racers usually use DOT 4 or other Non-DOT rated fluids with higher dry boiling
points (But which absorb water very quickly), and change their fluid *often*.
DOT level DOT3 DOT4 DOT5
Dry boiling point, min. 205C (400F) 230C (450F) 260C (500F)
Wet boiling point, min. 140C (280F) 155C (310F) 180C (350F)
Viscosity at -40degC 1500 1800 900
(centistokes)
-----
Me? I use DOT 5 in my lesser used cars (34 MG, etc.), and Castrol LAM DOT 4 in
my full time street and race cars, which get frequent fluid changes. Most
problems I've seen are due to corroded or pitted cylinders, old seals, and old
fluid.
________
/ _ \ Roger Garnett (Roger-Garnett@cornell.edu)
/ /|| \ \ Agricultural Economics | The Wayward Sports Car Centre
| |\/ || _ | 3 Warren Hall | http://www.wayward.team.net/
| | || | | Cornell University |
\ ||__/ / Ithaca, N.Y. 14853-7801 | (607) 533-7735
\________/ (607) 255-2522 | Safety Fast!
|