Hi Allen,
I found the article at the other end of your link to be very interesting, albeit
very unscientific. I wish I could claim expertise in every discipline the author
touched on, but I cannot. However, there were a few in which I have modest
knowledge, and they stopped me cold:
"According to Car Design and Technology Magazine (Dec. 1991), the biggest source
of water contamination for the fluid is osmosis through the rubber flex lines."
Water does not pass through rubber flex lines by osmosis (or any other process.)
Whoever wrote that must have been drinking too much Merlot or was getting paid
to
create myths and legends. A silly statement like that casts doubt on the
accuracy
of his entire treatise. What good would rubber seals and O-rings be if water
could pass through?
"This explains why the fluid in the calipers is always nastier than the fluid in
the reservoir, and why in a neglected brake system calipers corrode into a state
of uselessness long before master cylinders."
I can't speak for pony cars (most of their MC reservoirs were cadmium plated),
but this is the exact opposite of what I have found in the process of restoring
more than 20 LBC's. Master Cylinders failed and were replaced most commonly
judging by the number of cores I inherited from DPO's with each car purchased.
Ask the list how many have found major corrosion damage under the MC. Next most
common were brake lines, then slave cylinders, and last come calipers. Water was
entering through the MC breather hole, and damaging components sequentially
through the system.
I can go on, but don't want to belabor my position. The article is full of
inaccuracies and overstatements in all areas ranging from the air bubbles
(pretend it's nitro glycerin and you won't need to be concerned with teeny
bubbles), to silicone's lubricating properties, which are legendary (and
factual).
I think it is our duty to foster this debate, and propose that we change the MG
slogan from "Safety Fast" to "Safety Fast... and never stop arguing about brake
fluid." ;^)
Jim
Ajhsys@aol.com wrote:
> More on DOT 5 fluids in this post from a Mustang SVT page.
>
> http://olympiakos.com/svt-faq/node19.html
>
> Apparently this guy races and has some experience. Since racers usually
> change their brake fluid before each race, longevity of DOT 4 isn't an issue.
>
> One last thing, if you have another car with ABS, do not use DOT 5 silicone
> brake fluid in it. It does not contain the lubricants needed by the
> hydraulic pump, and it holds air bubbles really well, which can be caused by
> the pump when the ABS kicks in. Air in your brake lines is not good.
>
> Allen Hefner
> SCCA Philly Region Rally Steward
> '77 Midget
> '92 Mitsubishi Expo LRV Sport
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