In praise of Alfas/clutch master cylinder

[Tony Lupton <t.lupton@domain.elided>]

Hi all,

Two weeks ago, my 90 got sideswiped when the driver of another car
pulled out from the kerb without looking. Since then, I have been
driving an assortment of borrowed vehicles (I was without a headlight
and the clutch was playing up). This morning, I drove the 90 to the
panel beaters (having eventually located all the required parts).
Despite the road noise coming through an imperfectly-sealing door and
the knowledge that the car was cosmetically *ugly*, not one of the cars
that I drove over the last two weeks was as much fun to drive. 

Two good things
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1. Despite damage to three panels and a headlight and an estimated 
   AUD1000 in labour, at no stage did my insurance company (AAMI) make 
   any attempt to write the car off.
2. The digest came though when it came to finding a headlight. I put out 
   a plea last week, and found two NOS items (Oz and NZ) and three 
   second hand ones (NZ, Macau, and UK) in a week.

One bad thing
- -------------
I'll be without the 90 for a couple of weeks, so am stuck driving a
landcruiser trayback.

One bad thing turned good
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Never assume that anything on your car is put together the way it should
be. In the course of nearly two years ownership, I've found plenty of
little things that confirm this, but this one takes the cake.

After the accident, I was getting a horrible grind engaging reverse and
first, and occasionally on first-second (not the usual too fast a change
on a cold box). Discussion with the assessor and my usual Alfa sources
confirmed my thought that it was probably unrelated to the accident,
merely coincidental.

Anyhow, the diagnosis was a bad clutch master cylinder, so I purchased a
kit and just to be on the safe side, a spare spring. Out comes the
driver's seat and the clutch master (not a fun job). Dissemble the
clutch master and find lots of very gungy fluid, but all seals appear to
be intact, and the spring is ok.

Clean everything up and reassemble with the new kit. Hmmm, this doesn't
look right. There's no instructions with the kit, or in the shop manual,
which skips from removal to installation. Of course it's day one of a
four-day long weekend and nowhere is open (and I don't have digest
access at home). Ok, so I'll pull the one from the Alfetta, which was
going to come out at some stage anyway. Nope, the 90 uses an Ate, and
the Alfetta a Bendatalia. Oh well, I'll just put it back in the same way
it was when it came out. Except for the last two weeks, it's worked
properly for nearly two years. So back in goes the master cylinder and
the seat (foolish, I know). Time to bleed. There's *nothing* coming out
of the slave bleeder - no fluid, no air, no nothing. Remove the line
from the master - same story, no action there. Then I look at the
reservoir - fluid is being pushed back into the reservoir. Something is
very, very, wrong.

Out comes the seat and the master again (I'm getting much faster at this
now). I'm fiddling with the master cylinder internals on Tuesday morning
waiting for the parts place to open, looking at seal directions etc when
it all clicks into place and makes sense. The spring and the operating
seal had been in the *wrong* way. Opening time (at the parts place, not
the pub) rolls around and a phone call confirms the arrangement of the
master cylinder internals. Reassemble the master, install it, and put
the seat back in (I'm confident this time). Voila it all works - except
for when I let the level in the reservoir drop too far, forgetting that
the clutch off-take is out the side of the resevoir :-( Brake fluid is
cheap.

For anybody that cares to look, I'll write the whole thing up and stick
on my web page.

So how was this related to the accident? My guess is that somewhere
non-critical in the system there was an air bubble. The bang moved it to
a critical location.

The bigger question is how the DPO managed to get the clutch to work
after putting the master cylinder together incorrectly. I'm guessing DPO
rather than PO's mechanic because the master cylinder bore looked like
it had been honed with steel wool, and there were fragments of what look
suspiciously like steel wool coming out of the slave bleeder when I got
things working. On second thoughts I'm not even sure I want to know.

Curiousity question: What is the function of the holes through the
leading flange in an Ate clutch master cylinder piston?

Thanks,

Tony
1979 Alfetta 2000 (in mechanical bits)
1985 Alfa 90 2.5i (in cosmetic bits)
The Alfa 90 page http://www.geocities.com/MotorCity/Downs/7709
- --
Tony Lupton                          *     Astracon (Australia) Pty Ltd
Learning Products Team Leader     *    *   339 Coronation Drive
Email: t.lupton@domain.elided       *    PO Box 1643
Phone: +61 7 3259 2382                     Milton Qld 4064
Fax:   +61 7 3259 2259              *      Australia

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