Re/type of brake fluid to use and why. First, DOT3 fluid is not
hydroscopic, it is hygroscopic,i.e. it will readily take up moisture and
retain it. Have you ever seen what happens to a steel can that has brake
fluid in it? Where the metal is bare it will rust in no time. Think of what
is going on inside of your brake system! Moisture will enter even through
the rubber components. The silicone fluid is a definite advantage for two
reasons 1) It"s boiling point is much higher. Why? Because it does not
attract and retain moisture. When moisture is introduced into a system, the
fluids' boiling point goes down considerably. 2) By eliminating moisture in
the system, you eliminate the components corroding and sludge forming also.
The belief that silicone is a cure all is also a falacy. People think you
can put it in and forget it. NOT TRUE. Though silicone fliud does not
attrach moisture, there is still moisture in your system.The system is not
air and water tight. What happens after awhile is the moisture that entered
the system will accumulate in the low spots of the system. No,it will not
mix with the fluid,but it is still sitting there and will lead to rust and
corrosion. That is why it is recommended that even with silicone you bleed
the system once a year, to rid the system of ANY moisture. Whenever I
restore a car ,I will replace all rubber components, flush the steel parts
w/ denatured alcohol or replace them,then add silicone fluid. I have done
this for the past 12 years and never have had a problem. Hope this helps
George.
-----Original Message-----
From: Greg Monfort <wingracer@email.msn.com>
To: Pugsracer@aol.com <Pugsracer@aol.com>; bricklin@autox.team.net
<bricklin@autox.team.net>
Date: Monday, August 10, 1998 6:29 PM
Subject: Re: Fw: Brakes
>First things first. I said silicone brake fluid is hydroscopic. Why?
>Who knows, it's non-hydroscopic. I was talking about a racing spec
>brake fluid, not Dot 5 (a silicone based fluid, not quite the same
>thing), which I had completely forgot existed since it has no real
>advantages for passenger car use. The problem is that moisture is
>introduced into the system around seals. Since it doesn't blend with
>the fluid, it stays along the walls of components and initially
>corrodes the surfaces. Under racing conditions, high fluid
>temperatures break it down adding air bubbles to the system. Not
>pleasant when braking for a hairpin at 150+. Dot 5 is better for
>racing due to it's higher boiler point, but needs to be bled
>frequently. I doubt autocrossing and I know street driving won't get
>Dot 5 hot enough for aeration, but I'm surprised corrosion hasn't
>been a problem. Dot 4 really is the best fluid for street use.
>
>GM
>-----Original Message-----
>
>
>>Greg
>>I am not sure why one would need to bleed brakes all the time with
>Silicone.
>>Although I have heard that under flat out racing silicone doesnt
>seem to work
>>as well as regular fluid. I havent bled my Spitfire in over 8 years
>and it
>>sits a lot. I believe silicone is dot 5. Pugs
>>
>>Also our autocrosser has not needed brake bleeding in 2 years.
>>
>
>
>
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