[alfa] '86 Spider clutch pedal pivot shaft

[Michael Tiefenback <tiefenback@xxxxxxxxxxx>]

Gentle folk,

In progress: '86 Spider to be put back on the road.  Problem at
hand: clutch pedal not working.

As found -- clutch pedal with only about 1" travel to firewall, but
could pump up clutch to allow for engage/disengage transmission.  I
called a vendor for some other parts for this and other cars, and
asked about the reason for the pedal malfunction.  Salesman quite
accurately pinpointed a broken pivot shaft arm and sold me another.
Last weekend, I finally got time to install it, hoping for the
best.  I installed it.

While bleeding the clutch system, almost immediately after we
started getting hydraulic pressure, the pedal gradually sank to the
floor again, closer to the floor with each push.  woe.

I was confident that I had made some mistake with the keeper pin,
being a novice.  I disassembled it, couldn't find anything strange,
reassembled it ever so carefully.  I even tried assembling it
outside the car to check on retainer key engagement, in case
I wasn't getting the key in properly.  All looked well.  Next bleed
cycle, clutch pedal drops gradually to floor.  Woe.  I concluded
didn't know Spider clutch pedal assembly techniques.

Disassemble, examine, reassemble, torque key nut so hard I strip its
threads.  Woe and Sadness.

Disassemble and beat broken pivot pin key into place with hammer to
check engagement.  Same as before.  Consternation.  Call vendor to
order new key to replace destroyed one. $10 + shipping; next day
arrival.  One week work delay waiting for weekend.

Fast forward to today.  Reassemble ever so carefully.  Takes
increasingly familiar 5-10 pushes for pedal to drop to floor when
hydraulic pressure is recovered after bleeding air from cylinder.
But by now I am smart enough to be doing the initial bleeding of the
M.C. at its output, instead of from under car.  Another
disassembly/reassembly cycle, complete with using a BIG C-clamp to
try to press the key into the hole.  And then a vise.  (Yes, I am
installing the pin from the front of the car, with the nut on the
driver's side.  It was found that way and besides that, the geometry
looks proper.)  I could not find any sign of slippage at the
retainer pin, and I was mystified.  Pedal hits the floor again.  But
this time, I found that it is the pivot shaft to arm joint that is
yielding.  The new pivot shaft seems faulty.  At least I am not a
complete idiot, unable to install a simple retainer key.  I think.
Other options exist.  A bit later, the pivot shaft arm falls off.

Comments & Questions:
Anomalous resistance of the clutch could cause the pivot shaft to
yield as a weak link.  Is it possible for the clutch flex hose to be
partially plugged and make increased resistance to motion?

The clutch seemed to actuate properly, and even with the old
partially yielded shaft, the clutch would still pump up to disengage
without shearing off the arm.  The old shaft only broke completely,
so even I could see it was at fault, after my son and I pulled the
clutch pedal up to level with the brake pedal a couple of times and
watched it shear back to the floor after a few pull-pressure pumps.
It kept sagging, and finally separated at the arm weld to the shaft.

Have any of you a hint about other clutch actuation problems that
might require increased pedal pressure and breakage?  It really
doesn't feel any different from the pedal pressure of our '79
Spider.

Michael
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