[TR] [EXTERNAL] Re: Brake fluids again

[Randall]

Supposedly, methanol (methyl alcohol, also known as wood alcohol) is safer
for brake components than isopropyl.  I used methanol on my previous TR3A,
back around 1985 or so, and it did seem to get all the old fluid out.

My concern was (and is) then getting all of the methanol (or isopropanol)
out of the system before buttoning it up and adding brake fluid.  The
alcohol obviously has a much lower boiling point than brake fluid, and if it
does boil, you lose your brakes.  Of course you can blow the lines out with
air, but shop air often has a very high moisture content and you risk
winding up with water in the lines.  Dot 3/4 will absorb the water of
course, but one of the shortcomings of DOT 5 is that it will not combine
with water.  And the air compressor I had then would literally spit water
when using an air gun.  So instead, I used "canned air" as normally used for
cleaning PC boards and such.  
Eg https://amzn.com/B07QJY6MKD
(It's actually a kind of refrigerant, not air, but is moisture-free and acts
like air.)

Not really hard data, but that's what I've got.  BTW, the TR3A did continue
to have brake failures over the next few years, until eventually all the
seals and hoses had been changed.  The hose to the rear axle collapsed
internally, forming a check valve that made the rear brakes drag and smoke.


It then went a decade or more with no further hydraulic problems (before
getting rear ended and junked).

Also BTW, my local drug store actually carried methanol then, but I had to
ask the pharmacist for it and explain why I wanted it.  It's toxic to
humans, and they wanted to be certain I wasn't going to use it on myself.

-- Randall 

> 
> Randall (and others), any experience with a solvent flush 
> prior to bleeding in the DOT5?  ISTR an isopropyl alcohol 
> flush can do a better job of evacuating residual DOT3 than a 
> wet switch.  Makes sense, but I have no hard data.
> 
> I'm in the process of planning for DOT3 to DOT5 conversion on 
> my car, and I'm leaning toward leaving the existing rubber 
> seals in place.  If there are ways to do this that are better 
> than others, it would be good to know.
>