Re: Silicone brake fluid

[John Cooper <Jacques.Noir>]

At 16:13 07/29/96 +0000, you wrote:
>John Cooper wrote:
>> 
>> Please be more specific.  Silicone brake fluid is used in many and is
>> compatible with many brakes systems.  What do you mean that some seals will
>> get damaged?  Silicone is NOT a mineral based fluid, as it sounds like you
>> might think.  Silicone Dot 5 fluid is about as inert as you can get.  If you
>> have more specific information as to what will happen, I would be very
>> interested to know, and what specific materials used in automotive braking
>> systems it affects. Thanks,
>> Coop
>
>Coop,
>
>I think what he was getting at was the same type of things that I had
>heard.  DOT5 fluid is incompatible with standard DOT3 and DOT4.  If you
>want to convert a standard system then you must fanatically flush the
>system before filling with the DOT5 and if I remember correctly,
>(somebody please correct me otherwise!) DOT5 has an extreme tendency to
>absorb either air or water, so that standard flushing and bleed
>techniques must be employed much more often than normal.

Sorry, but current technology has this the other way round.  One of the main
reasons to convert to DOT 5 fluid IS to avoid the tendancy of glycerine
based fluids to absorb water (being hygroscopic), particularly in wet
climates, causing eventual corrosion of light metal parts, then the cast
iron ones.  I run DOT 5 in all my cars and those motorcycles that use
hydraulic actuation, and have done so now for some years.  No maintenance
necessary, particularly after long periods of being garaged.  NO other
industry uses glycerine based fluids ever, as it has far outlived its
usfulness.  Imagine some airliner stopping for the first ten feet, then the
sinking feeling as the fluid boils and it keeps on going throught the fence
using DOT 4 fluid.  Most of this information I got from a very extensive
article published in the national Jaquar Owner's Club magazine.  The author
was very adamant in suggesting that all Jaguar owners change over to the DOT
5 fluid to prevent puck seizing that was somewhat prevalent in older Jag
rear wheel cylinders.  If I can get a hold of the article I will post it
here.  Then you can judge.

Coop

>IMO, it would seem that for the amount of work involved, for a normal
>street car, to stick with a good quality, high performance DOT4 fluid
>such as Castrol GT-LMA or the ATE Super Blue.
>
>HTH!
>
>Gary
>-- 
>'85 Coupe GT
>Welches, OR
>
>---------------------------------------------------
>Gary G. Erickson
>Business Solution Integrators, Inc.
>503-702-5789       e-mail: erickson@teleport.com
>