I do it too! 30 years worth or mechanics work.. and specifically nearly 25
different LBC's ...I've always run a tube back up to my resevior from whatever
nipple I'm bleeding so I don't have to keep refilling it.
If you're concerned about crap in your system... you should be
flushing it to begin with. If you're really worried about recirrculating
some tiny pieces of crud, a small piece of cheese cloth and a rubberband
as a filter on the end of the hose solves that.
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: Rocky Frisco <rock@rocky-frisco.com>
To: mgs@autox.team.net <mgs@autox.team.net>
Date: Thursday, November 04, 1999 12:44 AM
Subject: Re: Clutch Bleed
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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