Rick,
I think and hope I have said this before, your reply is laudably pragmatic,
absolutely eloquent, and right on the money. I'm not just saying this because we
agree. Frankly, I succumbed this evening to the refusal by some members to
listen
to reason. I gave up. I can't force anyone to practice safety if after have it
explained to them they still refuse to follow it. You can lead a horse to
water...
I am so glad that you spoke up for their own best interests, and that of the
people with whom they share the road. I hope your comments made the impression
that you intended. You, sir, deserve a pat on the back.
MG's motto is Safety Fast. If there are any skeptics left, this whole diatribe
was
not a contest, it was and is about safety.
Jim
REwald9535@aol.com wrote:
> In a message dated 11/5/99 5:43:08 PM Pacific Standard Time,
> spaninc@ceibo.entelnet.bo writes:
>
> > Hi folks, here is my last take on clutch bleeding and fluid reuse. First of
> > all, there is no reason why "clean" brake fluid can not be recirculated in
> > a "clean" system. The fluid does not decompose or interact chemically with
> > any other substance and thus remains chemically stable for quite some time.
> > The fluid eventually absorbs water and thus losses some of its hydraulic
> > properties and is no longer inert to system materials. As far as the fluid
> > goes, it does not remain static inside the system. By design hydraulic
> > systems are dynamic and every time you press the pedal the fluid moves
> > inside the system, interacts with the system walls and moves around itself.
> > Recirculating fluid is thus safe as far as the chemistry of the fluid.
>
> Two problems here. First as you have said the fluid absorbs water. Also I'm
> not sure I would use the adjective "eventually" to describe the water
> absorption properties of brake fluid. This changes the boiling point of the
> fluid, and therefore the chemistry of the fluid. (One of the things you deal
> with in chemistry is changes of state liquid to gas in this case.) Brake
> fluid contains chlorates and chlorine is a very reactive element, so I'm not
> to sure about how stable the fluid is. Therefore your statement that this is
> safe as far as chemistry goes is not correct. Maybe I'm a little anal about
> this, but if you have ever gotten a set of B brakes hot enough to boil the
> fluid out of the calipers and have the pedal go to the floor, you might have
> a different point of view.
>
> > Lets talk particles, there are three important particles that contaminate
> > the system. Oxides from the system, dirt (in the form of dust, soil, etc)
> > and micro bubbles. How can you remove these? filtration. I would recommend
> > to put a filter on the end of the pipe that goes back into the system from
> > the nipple. Since I have access to laboratory materials I have managed to
> > use a VW gas tank mesh filter made of polyethylene with Whatman filter
> > paper No.1. This step will trap most all dirt of significant size that can
> > cause brake problems and also coalesce micro bubbles. I believe that
> > flushing the system before doing a serious bleed is of utmost importance.
> > Recirculation done safely and properly with a good final filter is possible
> > and can be a safe and fast way to bleed your brakes and clutch. Enrique
>
> Why would you go to all this effort? Regardless of you availability of
> materials this is a PITA. Also the only reason I could even consider doing
> such a procedure would be to save money on brake fluid, so I would have to
> ask if you can't afford brake fluid, how are you going to pay for the new
> front fenders and hood after the brakes fade and you smack something?
> Remember the fluid does not have to saturated for the boiling point to be
> lowered. Not to mention that if you have all this tubing running all over the
> place you run the risk of spilling a few drops of fluid on the paint
> somewhere and finding out first hand just what a great paint remover brake
> fluid is. (the Murphy factor)
> One last question if this were such a great idea why don't commercial auto
> shops, who go through more brake fluid in a week that the people on this list
> do in a year, do this? Two reasons, one both car makers or fluid makers say
> not to, and second you always going to leave some water in the fluid and
> therefore defeat the purpose of flushing the fluid. So unless you can
> convince me that you know more about hydraulics that the guy that designed
> the system and wrote the repair manual I'm gonna have to say No way.
> $.02
> Rick Ewald
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