[Healeys] Silicone DOT5 brakefluid for the 100

[Tom Felts]

The bottle of DOT 5 that I used in my cars years ago warns to not use it in brake systems containing DOT 3/4.  It does not say what will happen.  My guess is that if you drain the old 3/4 fluid out pretty good before adding 5, you will be OK.  A few drops of DOT 3/4 in a system full of DOT 5 is probably not enough to do any harm----so as to "changing" all components before adding 5 to a previously 3/4 system, I think that is overkill---and that is only based on a bunch of people's comments who just drained the 3/4 and added the 5 and have used it w/0 problems for years---including me.

tom

---- Richard Ewald <richard.ewald at gmail.com> wrote: 

=============
Do you have any kind of authoritative cite for this claim, or is this  
something that everyone just "knows"?  Inquiring minds want to know.
I have never heard this before.
Rick

Sent from my iPhone

On Nov 9, 2009, at 6:47, Oudesluys <coudesluijs at chello.nl> wrote:

> Tom,
> You should never fill up with DOT5 if you previously used DOT3 or 4.  
> You run the very serious risk that the seals will perish and the  
> system will leak like a sieve.