DOT 5 Silicone Brake Fluid

["Bob Smitter" <bsmiter@xxxxxxxx>]

"Anthony Dusovic" <adusovic@domain.elided> wrote:

>Subject: <Misc> Brake Fluid

>...... Silicone brake fluid creates a
>firmer pedal feel and is compatible with all types of braking systems."

>Everything that I have heard about Silicon fluid is exactly opposite in
>regards to pedal feel and compatibility with brake systems where standard
>fluid was used.  Does anyone have more information either way.  I agree
that
>it does not absorb moisture and does have a higher boiling point, but I
have
>heard that the brake pedal actually gets softer and it sometimes goes to
the
>floor at the most inopportune times???

Much to the horror of my BMW dealership mechanics, I started using
DOT 5 Silicone in my 1984 318i when it was one year old.  I didn't notice
ANY change in pedal feel - either brake or clutch.  What I did notice were
some suspicious wet spots under the car after only about another year.
The wet spots didn't have any odor, so I had no idea what was going on.
That was until the "BRAKE" warning light came ON and my clutch became
useless.  Seems that the silicone fluid found its way around all the seals
in
clutch slave cylinder!  We replaced both master and slave, flushed with
DOT 4, and I had no further problems through 1991 when I sold the car.
I did change DOT 4 yearly after that, and keeping it fresh kept pedal feel
fine.  YMMV

Bob

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