William B Noble (don't reply to this address) wrote in
article ...


you are having rust problems because brake fluid is hydroscopic


"Hydroscopic" refers to a hydroscope - an optical device used for viewing
objects below the water's surface.

Correct term is hyGroscopic.....absorbing or attracting moisture from the
air.

Common error...........


Alternatively, if you
are careful, you can use DOT 5 fluid, which is hydrophobic,

Meaning it does NOT absorb moisture. Having litrtle or no affinity for
water.

Therefore, any moisture in the system is NOT suspended in the fluid. It
goes, instead, to the lowest point usually the calipers and wheel
cylinders.

ALL braking systems have moisture in them.......

And, water is heavier than any brake fluid......



but you
have to be careful to not entrap air bubbles as you pour it into the
master cylinder.

I've seen anal-types pour DOT 5 ever so slowly into the M.C., then pump the
schidt out of it to bleed the brakes........

AND, you NEVER want to use DOT 5 with ABS........EVER!!!! ......for the
very same aeration reasons.


extensive tests have been done with DOT 5

......which concur with what I stated above.



REAL race cars are now using DOT 5.1 - drivers, crew chiefs, and teams
being fed up with spongy pedals and losing brakes when tiny pockets of
water in the calipers turn to compressable steam from brake heat.