If you have trouble understanding the dangers of that practice, all I can
suggest to you is to
call the brake fluid manufacturer for their recommendations.
I use DOT 5 silicone brake fluid. It is hydrophobic (it doesn't absorb water).
I change fluid
every 2-3 years. If the car has been idle for 1 or more years, I'll do it as
part of my safety
inspection and maintenance. Sorry, you lost the bet!
If you are a professional mechanic, I strongly urge you to consult your
attorney concerning your
liabilities for employing this risky technique.
Jim
wizardz wrote:
> We've been through this one before! You're not RE-USING brake fluid!
> Any idiot knows not to do that.
> If anything...you're using the fluid YOU ARE ALREADY RELYING ON!
> When was the last time you bleed your brakes? I mean completely
> flushed and refilled as suggested by every manufacture.
> Is it part of your regular maintainance ritual?
> DO YOU DO IT A MINIMUM OF EVERY TWO YEARS? I'll bet not!
>
> I do.
>
> >>You, my friend, have a lot to learn (IMHO). You migh
> that's all it is... YOUR OPINION.
>
> Paul Tegler
> OBie - 1973 BGT - Daily Driver
>http://www.teglerizer.com/mgstuff/ob_description.htm
> Rat - 1980 Spitfire w/ O/D - in re-hab
>http://www.teglerizer.com/triumphstuff/spit80.htm
> Punkin' - 1978 Spitfire - in Superb Shape!
>http://www.teglerizer.com/triumphstuff/spit78.htm
> Greene - 1972 Round Wheel arch MG Midget in the works
> email: wizardz@toad.net http://www.teglerizer.com
>
> -----Original Message-----
> From: James H. Nazarian <microdoc@apk.net>
> To: Rocky Frisco <rock@rocky-frisco.com>
> Cc: mgs@autox.team.net <mgs@autox.team.net>
> Date: Thursday, November 04, 1999 10:17 AM
> Subject: Re: Clutch Bleed
>
> You, my friend, have a lot to learn (IMHO). You might be amazed at the
> residues of junk that remain in your hydraulic system after a fluid
> replacement. Ever hear of surface tension, and viscosity? Want an illustration
> of how the stuff can cling? Fill a metal cup with any flavor brake fluid; DOT
> 3, 4, or 5; Empty the cup, and return a while later to see how much has
> adhered to the sides. Well, it is many times worse with small diameter tubing.
> Drain all your hydraulics. Blow the lines out with low pressure air. Refill
> the system and bleed it. Think you got it cleaned out??? Do it again in a few
> months and see what you get.
>
> If this method is standard operating procedure on American cars, it explains a
> number of things. Do yourself and those with whom you share the road a
> life-saving favor. Call any or all manufacturers of brake fluid, tell them
> your suggestion and ask how they feel about reuse of brake fluid. You'll hear
> an emphatic " DON'T ! "
>
> Don't count on seeing dirt in a "clear" plastic tube as someone pumps the
> pedal. The fluid velocity is too high for anyone but Superman to see anything
> less than the size of a golf ball sail by. Another purpose of changing the
> fluid (DOT 3 & 4 only) is to deal with a well known drawback of those brake
> fluids: they are hydrophilic; they attract water. Water in your brake lines
> will corrode metal parts. The old fluid is contaminated with moisture and
> particulates; get rid of it.
>
> So, you've rebuilt many master cylinders but haven't noticed any tiny
> orifices. That is truly frightening. They are there; if you haven't seen them,
> you are not doing a very thorough job of rebuilding. What you are doing is
> potentially dangerous. Because you have been doing something wrong for a long
> time does not make it right; it makes it a bad habit that you should break. I
> can provide photos of the interior of an MGA master cylinder, clearly showing
> the orifices you doubt the existence of. If any MGA 1500 or 1600 listers want
> to see it, along with instructions for a complete rebuild, you'll have to
> e-mail me direct. Unfortunately, I do not have a comparable package for the
> MGB.
>
> The frequency with which you claim to do hydraulic fluid changes is
> commendable. I guess your cars must certainly have among the cleanest
> hydraulic systems in the world, and moisture in your brake lines is probably
> held to a minimum. After all, how much moisture can collect in six months.
> But. . . you are still wrong to use a fluid recirculation method, and even
> worse to recommend it to others; only one itty bitty speck of dirt, or rust is
> necessary to disable the brakes. Have pity on those with whom you share the
> road.
>
> Jim
>
> Rocky Frisco wrote:
>
> > James H. Nazarian wrote:
> > >
> > > Hi List,
> > >
> > > I received a general message today that relayed an idea for bleeding the
> > > clutch slave cylinder. It seems the recipient was advised to run a tube
> > > between the clutch slave cylinder nipple and the Master Cylinder lid,
> > > and pump the hell out of the clutch. The idea sounds clever until you
> > > realize that besides removing air, you will very likely pump a piece of
> > > dirt into your MC that could result in you losing your brakes or clutch
> > > at a most inopportune moment. I can assure everyone, it does not take
> > > much of a speck of rust to block the replenishment orifice in the MC of
> > > an MGA 1500/1600.
> > >
> > > NEVER REUSE BRAKE FLUID. Even if it is for the clutch. There are some
> > > very small orifices in the hydraulic cylinders that can be obstructed by
> > > some surprisingly tiny bits of dirt or rust. One of the listers told you
> > > the correct procedure and proper sequence of tighten nipple, press
> > > clutch, loosen nipple, tighten nipple, release clutch, etc. Follow his
> > > instructions, and DON'T PUMP ANY FLUID BACK INTO THE MASTER CYLINDER:
> > > DON'T!!!!!!!!!!!!!!!
> > >
> > > For safety reasons I feel obliged to alert the list. It is not done to
> > > embarrass anyone. We are all here to learn from each other's
> > > experiences, and to share our own knowledge. So it is with the best
> > > intentions that I say, DO NOT PUMP FLUID BACK INTO YOUR MC. PLEASE!!!
> >
> > Let's name names. I, Rocky Frisco, said that's how I bleed my brakes and
> > clutch, and have been doing it that way without problems. First I drain
> > the lines entirely and then refill with new fluid. Where's this piece of
> > dirt going to come from? If it's already in the brake lines, after
> > draining completely and refilling (deosn't everybody do this?) I will
> > see it coming through the clear plastic line. That's why I specified
> > clear plastic line and watching what's coming through it, bubbles, etc.
> >
> > This procedure is standard operation to bleed and prepare American
> > vehicle master cylinders and I've found it also works well when an
> > English or German MC will sometimes not set up on its own. My method
> > just adds the rest of the system. I've rebuilt lots of master cylinders,
> > admittedly not every model used on LBC's, but many of them. I've not
> > noted any tiny orifices that might cause the brakes or clutch to fail if
> > blocked by a speck of dirt.
> >
> > I have *never* yet seen a British car get fully bled by using the pump,
> > loosen, tighten, pump, loosen, tighten, pump, fill etc. etc. method
> > loved so well by American mechanics. It always leaves some air in the
> > system. The difference between this and a really air-free system is
> > unmistakable. Besides the recirculating bleed, I also put pressure on
> > the brake pedal overnight after renewing the fluid. Not completely sure
> > why, but this hardens the pedal even more.
> >
> > My alternative bleeding method is tube-in-bottle, open bleeder, pump
> > slowly until no more air is visible (somebody else keeping the MC full).
> > This gets better results than the pump-up method, but still not as good
> > as the recirculating method.
> >
> > I understand it's common for people to leave the brakes and clutch
> > hydraulics alone until something breaks. Most owners won't pay any
> > attention to the brakes until the pedal sinks toward the floor or they
> > find a bad leak and fluid all over the driveway or they hear
> > metal-to-metal when they stop. I renew the whole system, metal lines,
> > flex lines, cylinders and all, at least once every five years and I
> > drain and refill with fresh fluid when I do the prep for the season
> > change in the fall and spring.
> >
> > Tapping on the cylinders and lines will almost always dislodge more air.
> >
> > Perhaps I erred in taking for granted nobody would pump old, dark,
> > crappy fluid through a system. I don't recommend that inexperienced
> > people service their brakes or steering anyway, too dangerous. This is
> > something that should be left to or learned from a good mechanic.
> >
> > -Rock
> > --
> > Rocky, JJ Cale Band & Pratchett Books: http://www.rocky-frisco.com
> > Rocky's Mini Cooper Page: http://www.geocities.com/MotorCity/6437/
> > Mini Books: http://www.geocities.com/MotorCity/6437/rockboox.html
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