[Spridgets] Master cylinder maintenance

[Bud Osbourne]

Rick,
Silicone brake fluid and glycol based brake fluids (DOT 5 and DOT 4
respectively) are "chemically incompatible", meaning they will NOT combine
and therefore cannot blend together to form ANYTHING.  This I learned a few
years back, from an article (in Vintage Truck magazine, an EXCELLENT
publication) written by a chemical engineer.  He was pretty specific about
it, as well as pretty adamant.  The guy has his own restoration business,
specializing in vintage trucks, so he's had a lot of experience with this
sort of thing.
Personally, I've gone from glycol to silicone brake fluids, in more than one
vehicle, with no ill effects whatever.

Bud Osbourne

-----Original Message-----
From: spridgets-bounces at autox.team.net
[mailto:spridgets-bounces at autox.team.net] On Behalf Of Rick Fisk
Sent: Tuesday, July 10, 2012 4:21 PM
To: spridgets at autox.team.net
Subject: Re: [Spridgets] Master cylinder maintenance

Phil,

Unfortunately, it's next to impossible to remove or flush the silicone brake
fluid from your brake system.  Any trace of silicone brake fluid remaining
will react with glycol based brake fluid and form what has been described as
"gelatinous goop".   This goop can plug orifices.  The only surefire way to
completely eliminate it is to replace all of the components of your brake
system, including the lines.  I recommend you repair the leaky bits and
continue to use silicone brake fluid.

Silicone based products are so difficult to clean up that they are banned
from any automotive plant that does any painting.  A few years ago I helped
pull some new coax video cables through a GM plant where they do
electrostatic painting of replacement sheet metal parts.  We had a small jug
of a wire slick product that had .01% silicone in it sitting on our lift.
We hadn't used it, it was just on the lift.  When the plant guys discovered
the wire slick they just about came unglued and we were nearly thrown off
the site.

Rick

Sent from my keyboard

On Jul 10, 2012, at 3:00 PM, Philip Nase <nases at verizon.net> wrote:

> I've been using silicone in my Bugeye master for 4 years but I noticed 
> some fluid on the pedal pads during a long ride yesterday. The MC 
> rubber I had
was
> supposed to be for use with the silicone but maybe 4 years is too much 
> to expect.
>
> Anyway if I switch to conventional  fluid what should I flush the 
> system
with?
> And do I need to replace anything that is currently ok such as hoses 
> or
wheel
> cylinder rubbers?
>
> I initially used the silicone to help save my paint from mishaps but 
> may change now.
>
> Thanks.
>
> Phil Nase