>The bottom line is this. If you have a pretty car you drive gently, take to
>picnics, display in parades and the like, use silicone. Your stuff will last
>a long time and spills are harmless. If you drive the wheels off it, use LMA.
>Otherwise, those tiny damned air bubbles in the silicone will expand to the
>size of marbles when your brakes get hot and make your life a little too
>interesting.
If you don't believe Phil, you probably won't believe me, but he's right.
And if you don't believe us, maybe you'll believe Tilton Engineering of
Buellton, California, makers of some of the world's best high-performance
hydraulic gear. At least five years ago when I was troubleshooting the
braking system on my Midget, Tilton recommended DOT 4 (specifically Castrol
GT LMA fluid) for general-purpose and competition use, for exactly the
reasons Phil gives -- too hard to get the minuscule (invisible) air
bubbles out, so at best you've got a spongy pedal and at worst you get
the premature and stochastic wheel locking Phil describes. (Mine never
got that bad, but it always felt like the brake pedal was connected to an
air mattress when I stepped on it -- boing, boing, boing.)
Miq Millman has had some success with a valve he has designed that helps
the fluid trickle into the master cylinder rather than "glugging" in from
the bottle. If the mailer is accepting messages there, you might get him
to send you a description of this thing.
You already know, of course, not to use DOT 3 fluid in your MG, yes?
Eats the rubber seals in fairly short order.
--Scott
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