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VERY long post-Recent Clutch Wisdom

To: "Michael L. Hendrick" <104405.1163@compuserve.com>
Subject: VERY long post-Recent Clutch Wisdom
From: "David E. Brown" <spmsales@rust.net>
Date: Tue, 07 May 1996 01:55:14 -0400
Mike, here is a small portion of recent list info on the subject 
of Midget clutch bleeding:

-Dave

Subject: 
         MG Midget clutch 
   Date: 
         Wed, 10 Apr 96 08:04:24 -0400 
  From: 
         ALAN_COSTICH@HP-USA-om11.om.hp.com
     To: 
         mgs@autox.team.net


Item Subject: cc:Mail Text
          Jon,
          
          I know your misery. I'm still working on mine. What does
          seem to help is:
          
          With the bleed tackle still hooked up to the bleed screw,
          crawl underneath, disconnect the push rod from the throw
          out fork, have your assistant open the bleed screw while 
you
          push the piston of the slave all the way in with the push
          rod. When the piston bottoms, close the bleed.
          
          Repeat as required.
          
          Also, make sure the master cylinder has been bled. Loosen
          the pipe at the top of the cylinder, have your assistant
          press the pedal. Fluid should flow from the join. (Make
          sure the painted surfaces are protected.) Tighten the 
join.
          
          Keep us apprised.
          
          Alan

Weekend before last, I replaced the clutch master and slave 
cylinders in my
B.  There had been a lot of discussion on the list just before this 
about
how hard it is to bleed a clutch and I didn't remember it being that 
bad,
but my last experience was 15 years ago.

Years ago, I owned a '79 Spitfire and when I replaced the master 
cylinder,
I let the car sit for half a day and then pumped the pedal a couple 
of times
and the clutch was bled, but the clutch line in a Spit is strictly 
vertical.

After the new cylinders were in the B, I bled the clutch at the 
slave cylinder
with my boyfriend working the pedal.  This obviously wasn't doing 
any good.
Then we bled at the connection to the master cylinder.  This 
actually caused
the actuating rod down at the clutch to move and the clutch could 
then be
pumped up so that the car could be shifted, but at a certain point, 
it became
obvious that no amount of bleeding at this location was going to get 
all the
air out of the system.  I was out of clutch bleeding time and I had 
to drive
the car to work, so I drove it pumping furiously on the clutch pedal 
every
time I needed to shift.  After three days of this, the clutch no 
longer
needed to be pumped up--it had bled itself.  I'm not sure if I'm 
recommending
this as a procedure to be followed because pumping up the clutch for 
every
shift is tricky.  I'm a trained professional and can do this while 
eating a
carne asada burrito.

Someone (Motorhead?) suggested pushing the slave cylinder rod into 
the slave
cylinder after the system had been bled as much as possible.  Based 
on the
geometry of the system, this should work, but I don't know how 
difficult this
is because I've never done it.  If I were going to do it, I'd use a 
big pair
of water pump pliers to push the end of the rod into the slave 
cylinder
housing with the cap off of the master cylinder.

Good luck!

Denise Thorpe
thorpe@kegs.saic.com


Subject: 
         Re: MG Midget clutch 
   Date: 
         Sun, 7 Apr 1996 20:06:19 -0400 
  From: 
         KGSTUART@aol.com
     To: 
         jbreen@ncpi.com, mgs@autox.team.net


The Midget is a very tough car on which to bleed the clutch 
hydraulics.  It
has to do with the angle of the mounting of the slave ctylinder and 
the
position of the bleeder screw. The problem is that there is quite 
often a
pocket of air left in the cylinder, no matter what you do. It is 
amazing how
small a pocket of air will keep the system from operating.  Try the
following:
1. Unbolt the slave cylinder, but leave the hydraulic line attached. 
Let it
hang under the car. Loosen the bleeder screw and let the fluid 
dribble out.
The idea here is to let gravity help you "prime" the system. Once 
the fluid
is flowing freely, bolt the unit back onto the car, and bleed as 
usual.
2. Crawl under the car, unbolt the slave cylinder, but leave the 
hydraulic
line hooked up. Let it hang below the car. Remove the actuating rod 
and the
dust boot. Get a c-clamp and fit it so that the pison is locked in 
the slave
cylinder. Bleed the system, while holding the slave cylinder such 
that the
bleeder screw is the highest point of the cylinder.
3. If the above does not work, this will........Buy a pressure 
bleeder. There
is one made by Gunson that works well. I have also heard good things 
about
the Mityvac system. They run about fifty dollars, but it will blow 
the air
out of that system in 10 seconds. Well worth it........
4.  Also, ,,,,,,Check that there is no wear on the clevis pin or the 
shaft
hole of the slave cylinder actuating rod. If there is any wear on 
these two
parts, it will cut down on the length that the clutch fork will 
travel.

Good Luck.


Jon D. Breen was asking about cluych bleeding problems on Midgets. I 
have
just replaced the clutch in my '70 Midget over the winter. After 2 
days of
lying on my back while my neighbor pumped the pedal , the clutch 
finally
works. After trying normal bleeding methods i finally took the slave 
cylinder
off the transmission and wrapped Teflon tape on the bleed screw and 
put it
back in. Using a vacuum bleeder and most of a bottle of Castrol LMA 
fluid we
finally got all the air sucked out of the line. Seems like the 
bleeder screws
are a little sloppy when you try to open them enough  to get a good 
flow, and
will get some air back into the system and defeat your purpose. Give 
it a
try: at least it worked on mine.
George Chase
GeorgeC70@aol.com
'70 MG Midget


ubject: 
         Re: MG Midget Clutch 
   Date: 
         Sat, 6 Apr 1996 09:34:55 -0500 
  From: 
         RJohn50603@aol.com
     To: 
         GeorgeC70@aol.com, mgs@autox.team.net


George,

My son and I have had exactly the same experience on our 1976 and 
1979
Midgets. The clutch servo on these cars is difficult to bleed. It is 
probably
because of the large inside diameter of the hard plastic tube 
between the
master and slave cylinders and the high spot in the tube which is 
unavoidable
with the design layout. You simply cannot get the velocity of the 
fluid to
get the bubbles pulled down and out of the slave before you have to 
stop and
refill the master.

My 73 MGB isn't this bad. Of course the diameter of the tube between 
the
master and the slave is metal with a smaller I.D. for the greater 
part of the
distance.

A Toyota wagon my wife and I had would actually BLEED ITSELF by 
gravity
simply by filling the master because it was down hill all the way. 
All the
MG's I have seen have that high spot. Seems like the engineers 
designing the
system never had to bleed one or they would have followed the Toyota 
scheme.

                                                                       
R
Johnson - Dallas

Subject: 
         Midget Clutch 
   Date: 
         Mon, 8 Apr 1996 21:57:38 -0500 
  From: 
         Michael Chaffee <mchaffee@ux1.cso.uiuc.edu>
     To: 
         MGs <mgs@autox.team.net>



For those of you faint of heart, I can vouch that at least on the 
'74
Midget, clutch bleeding can be accomplished by two people with some 
time
and a hose.  I'm sure it's easier with one of the magic tools, but I
don't have one of those.

While we're on the subject of clutch drag, let me mention one other 
source
of clutch problems that may not be intuitively obvious at first:  
the
thrust washers.  When I first bought my Midget five years ago (Five 
years!
And it seems like only yesterday...), it had a severe clutch chatter
problem.  Replaced the entire clutch, and now it not only chattered 
but
dragged a bit as well.  I lived with it that way for a few months, 
then
finally decided to replace it.  New clutch, replacement confirmed 
good
flywheel - still chattered, still dragged just a little.  Fast 
forward to
this last Labor Day.  I finally got around to replacing the engine, 
and
discovered two things: 1. The old engine had roughly 1/8" free play
forward/backward on the crankshaft (I still can't believe it didn't 
hurt
itself like that), and 2.  The new engine's new clutch does NOT 
chatter or
drag at all.

I think the two things are related: if the clutch is an extra 1/8"
away from the T/O bearing, it might be enough to cause drag, and, 
like
suspension bushings and brake shimmy, the tiniest runout in the
flywheel/clutch could be magnified significantly by the crankshaft 
moving
forward and backward, manifesting itself as one wicked 
grabby/chattering
clutch.

Just one more thing to think about in this whole mess, I guess.

Michael Chaffee
mchaffee@ux1.cso.uiuc.edu

CCSO's secretary has officially disavowed any knowledge of my 
actions.

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