Well, I wasn't going to forward "my method" to the list becasue I didn't
wanna get one of those private messages that start off with "don't be
such a cheap ass..." but since Aron Travis already started it off...
When rebuilding hydraulics, if the master or slave is made of cast iron,
then you can usually go after it with a honing stone with some succees.
However, it they are made of the usual aluminum of pot metal, a honing
stone just exiles them them to the junk pile faster -- the stones are
too coarse.
The wooden dowel trick ain't bad but I'm terrible at trying to cut a
well placed notch in anything plus you gotta git the right size wooden
dowel for each project.
What I have done with some success is start with a real long drill bit
-- I have a 10 incher for adding phone wire through dry wall (used for
that purpose about twice). It is a 1/4 inch.
I then cut a strip of emory paper (very fine wet/dry sandpaper) that is
deeper than the MC/slave cyclinder and about 4 inches wide (a half
sheet). I duct tape the long edge of the sandpaper to to the drill bit
so that about 1/2 inch is hanging off the front. Rolling the paper
around the drill bit in the direction of rotation makes the hone.
Then you discover that it doesn't remove material vary fast so then you
take strips of newspaper and lay it under the sandpaper to act as as
packing material until you build up the diameter to make it a tight
squeeze into the bore.
Once you've done that and if you are using fine sandpaper and if you are
using a good lubricant (I use marvel mystery oil), then you can spin the
drill at high speed in the bore for several minutes and only a minute
amount of the soft bore material is removed. It does a very nice job of
shining up the bore and will work real hard on corrosion.
You also need to figure out were the worst corrosion is with respect to
the rubber seals on the plunger. If the corrision is near the front of
the bore, it may be past the seals and is not a factor on making a
successful rebuild.
After that, I clean everything up with just soap and water, blow
everything real dry, and then put in the rebuild kit.
Bob Allen, Kansas City, '69CGT, '75TR6, '61Elva
Aron Travis wrote:
>
> Mark Endicott wrote:
> >
> > It's 7:30 AM and I am sitting here looking at the bore of the clutch
> > master cylinder from my 70 Midget. It's the small separate one unlike
> > the dual MC on the earlier cars. The interior wall has some wear on the
> > bottom part in the front of the bore, the deeper internal surface looks
> > OK. I wonder if these can be honed or otherwise polished and rebuilt,
> > since I have the kit. My gut says it's too far gone, anybody found one
> > at a chain parts store like NAPA?
>
> You can always get it sleeved. There are brake master cylinders hones
> that will work. Or, you can get a wooden dowel (small enough to fit
> in your drill), cut a small slot in it, put a folded piece of fine
> grit sandpaper (like 600 wet) in the slot, and spin it in the bore.
> Keep it wet, and pay attention, but you can clean up the bore this way.
> The dowel method works especially well on aluminium bores, like on
> motorcycles. A good cleaning can do wonders, and since it's a clutch
> MC, and therefore not a safty item, I would try the 'home' methods first.
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