[Healeys] Brake Fluid -- Silicone vs. glycol

'bluehealey' bluehealey at gmail.com
Mon Jul 26 05:54:46 MDT 2021

Now that is a perfect checklist Simon. Captures everything you need to know. 
In addition I work on the basis that glycol mixtures, if neglected (not flushed) for more than 3-4 years, can cause minor problems with the hardware. 
Silicone, if neglected for a similar period, can cause major problems with the hardware. 
Guess which I choose to use. 

AlanB - iPhone message.

> On 26 Jul 2021, at 09:57, Simon Lachlan via Healeys <healeys at autox.team.net> wrote:
> I was getting myself in a muddle over brake fluid once so I made myself some
> notes. Probably pinched from Google; I don't recall:-
> 1)    All brake fluid is "synthetic".it's not a "natural" product.
> 2)    Most synthetic fluids are NOT silicone. They are polyethylene glycol
> ether based.
> 3)    DOT 3 & 4, which can be mixed, are not silicone. They are glycol.
> 4)    DOT 5, which cannot be mixed with 3 or 4, is silicone. Can't be
> mixed with anything!
> 5)    DOT 5.1 is glycol based and cannot be mixed with DOT 5.
> 6)    DOT 5.1 can be mixed with DOT 3 or 4, as both are glycol based.
> The word "synthetic" began to appear when manufacturers worked out that it
> made regular brake fluid sound more special ie they could charge us more
> money for the same old stuff.
> DOT stands for Dept. Of Transport and relates to the fluids' boiling points.
> If a car brakes at high speed, the brakes get hot. Some heat is carried away
> from the brakes by the brake fluid. Bad news if the fluid boils! The faster
> you're going, the higher DOT you need. Higher DOT numbers indicate higher
> boiling points for "Dry" fluid (has not absorbed any water) and "Wet" fluids
> (has absorbed water). ie, the wetter it is, the more problematic it becomes.
> Mixing 3 with 4 lowers the boiling points and vice verca.
> _______________________________________________
> Support Team.Net http://www.team.net/donate.html
> Suggested annual donation  $12.75
> Archive: http://www.team.net/pipermail/healeys http://autox.team.net/archive
> Healeys at autox.team.net
> http://autox.team.net/mailman/listinfo/healeys
> Unsubscribe/Manage: http://autox.team.net/mailman/options/healeys/bluehealey@gmail.com

More information about the Healeys mailing list