The C6 Corvette had an issue with the clutch fluid going prematurely dark, unlike their owner's hair. Owners were advised that this was carbon black being released from the seals, made of the same material as on our Jags, nitrile rubber.

 

How do you propose to take water and hence corrosion out of the equation?

And no, not everyone can live in AU, NZ, Arizona, New Mexico, Texas.

Did you know that the most common point of water ingress is past the
caliper bore seal? Tiny on any given stroke, but lots of strokes in real
life. Again, perhaps not a problem in a dry climate or a vehicle never
driven in the rain. But a real life phenomona for everyone else.

 

Did you know , that a common cause of brake failure or low brake pedal complaint AFTER a bleed and flush , is due to a blocked or restricted compensating port !

That port is at the base of your reservoir , where the brake fluid sludge forms and builds up .

So it really doesn't matter where you put your "hammer" or "pump or brake pedal half -
way" or how much "moisture" is in the system , and for that matter what part of the world you live in .

Multiplecats , I have strayed from your original post and I apologise for that .

 

I've always wondered how it's possible for moisture to migrate inwards past the caliper seals, yet fluid doesn't migrate outwards.

 

Good point..For that reason, one should suck out all the old reservoir fluid as best they can and refill with fresh fluid before beginning the bleeding process...Maybe I'm being a little bit Capt. Obvious, but I didn't see it mentioned yet.

And Nitrile rubber seals contain NO CARBON

Properties and Applications
Nitrile Rubber (NBR) is commonly considered the workhorse of the industrial and automotive rubber products industries. NBR is actually a complex family of unsaturated copolymers of acrylonitrile and butadiene. By selecting an elastomer with the appropriate acrylonitrile content in balance with other properties, the rubber compounder can use NBR in a wide variety of application areas requiring oil, fuel, and chemical resistance. In the automotive area, NBR is used in fuel and oil handling hose, seals and grommets, and water handling applications. With a temperature range of –40C to +125C, NBR materials can withstand all but the most severe automotive applications. On the industrial side NBR finds uses in roll covers, hydraulic hoses, conveyor belting, graphic arts, oil field packers,

 

A bit lengthy and geeky but an excellent explanation of why carbon black is found in hydraulic system seals.

http://www.cancarb.com/docs/pdf2/The..._Compounds.pdf

 

"DPK" , I don't think your " being a little bit caped " your just saying what 'you' believe to be right , and so you should . If your happy to change your brake fluid every two years , then that's fine do it .

What I'm saying , flushing your brake fluid on a regular basis isn't going to prolong your
brake system , you will still need to do your caliper and master cylinder as they wear out
So what if the oil looks a little dark , it still retains viscosity , and thats what you want

Most people replace the fluid after brake repairs have been carried out anyway .

"plums" , as for your comment about water getting past the "caliper bore seal"
WHAT AN ABSOLUTE LOAD OF BULL **** IF EVER I'VE HEARD ANY

" tiny on any given stroke " , the heat from the brake pad alone will dissipate that water let alone the heat build up around the caliper .

Have a good day .

 

Thanks for that reply and you're quite right...But, Yeah and I'll be the first to admit..I am very OLD SCHOOL...Preventative maintenance has always served me well and it's cheap insurance..I don't try to prove the products wrong or prove they will last a life time..blah, blah, blah..Just that an ounce of prevention is a whole lot cheaper than a major repair...

Having said that ..I never ever replaced brake/caliper pistons seals or master cylinders in any of the many cars that I have owned over the years (50+) if I changed the brake fluid on a bi-annual basis..it has always worked well for me as I stated.