Smokey,
Pros and cons on repairing your own. Con: vendors who sell rebuilds have a
core charge, so cutting up your vacuum control will cost you a few bucks.
Pro: the knowledge you can fix one of these things if it goes south and you
don't have a spare.
Jim Carters have used ones for about $20, I ordered one a couple of weeks ago
and called last Friday to check on the status of my order. Apparently the
guy who pulls their parts is out sick, so what the hell, time to pull that
puppy apart.
First I removed the extraneous parts, particularly the internal spring which
comes out by unscrewing the part where the vacuum tubing connects.
Then I slapped a cutting wheel into the dremel and cut the control apart
along its edge, separating the two halves and freeing up the diaphragm. The
diaphragm had a 1/2" tear along the edge next to where its pressed between
the halves of the control body. As this is where the back and forth movement
occurs, it is not a good place for a tear.
The diaphragm on my unit ('53 216 1/2 ton) is made of rubberized fabric and
after a bit of trial and error, I settled on stitching it back together with
a needle and thread (the smallest I could find). I smeared a bit of clear
silicone over the stitching on both sides to seal it.
To put it back together, I drilled through the flanges for six tiny screws,
lock washers, and nuts. I smeared a little more silicone around the edge of
the diaphragm on the vacuum side, put it all together, and let it set up over
night.
I tested it with a Mityvac the next day. Its not perfect, it loses slightly
less than a pound of vacuum a second, which should have a negligible effect
on its functionality.
When my vacuum control on order comes in I'll replace this one and save it
for the next time, probably after fiddling with it a bit more until it gets
zero vacuum loss.
Barrett Revis
Sparks, NV
'53 3105
'48 3105
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