>Date: Sun, 3 Jan 93 19:46:11 -0700
>From: FLAKE_JOE/HPATC1_04%mailhub.cs.itc.hp.com@mailhub.cs.itc.hp.com
>Subject: TR6 clutch master/slave repair
>To: british-cars@autox.team.net
>The PO had spaced the slave cylinder back from its mounting bracket
>about .25 inch (real kludge ... looks like a small aluminum pulley
>under one bolt and 4 washers of various sizes under the other!). Any
>guesses why this might have been done? Related to this, the arm on
Three possibilities occur to me: 1) spacers are required but the
original ones were lost by some PO; 2) The original salve cylinder was
replaced by a different type. Perhaps some PO decided to use a cheaper
cylinder and used the spacers to make it work, or perhaps he had another
cylinder on hand and just wanted to make use of; 3) The push-rod on the
last replacement cylinder was longer than the original. When I replaced
the master and slave cylinders on my car, some of the push-rods were
longer than the ones on the original parts, even though the part numbers
were identical. I reused the old push-rods that were in good conditions
and shortened the rest to the prober length.
>The PO had also added an assist (?) spring connecting from the
>operating shaft towards the rear and attached to the frame (using
>a piece of coat hanger!). This is not a very strong spring but it
>would take up any slack in the mechanism. Perhaps just to stop a
I would think that the original setup had a return spring. Mine
certainly has one. Perhaps the PO just lost the original parts or
broke something and just kludged a fix.
>
>The inside of the master cylinder contained some of the nastiest
>crud I've seen in a long time. I'm going to try rebuild kits on
>both master and slave -- although some opinions here have been that
>the rebuild process is a waste of time and money. We'll see. It
>had been switched to DOT5 at some point in the past but I'm going
>to go back to DOT4. Opinions seem to vary, and since I plan to do
>a good bit of flushing to get any/all crud from the line the financial
>differences start to kick in. A quart of Castrol DOT4 was $6.xx at
>PepBoys -- the last silicon DOT5 I bought was $23.xx! Hurts when
>you buy this to flush through a system and throw away.
Originally I was going to rebuild all of my cylinders but I changed my
mind after discussing this with a Brit car mechanic friend. He was of
the opinion that rebuilt aluminum cylinders generally don't last. Also,
consider the labor involved in removing and re-installing these parts.
Do you really want to go through this again in a few months? That was
another reason I got new parts. My master cylinders were all
single piston type and were reasonably priced at $60 each, I felt when
considering the cost of the kit and value of my labor. The clutch
slave was a little pricey at $80 but worth the peace of mind, in my
opinion.
If you do decided to rebuild, don't use a regular master cylinder hone,
they take metal off to quickly. I think there are special hones
available for aluminum but I have no idea where you buy them. Use
crocus cloth or very very fine sandpaper. If you can't clean them up
that way then buy new parts.
I know some people have strong feeling about DOT4 vs DOT5. When I redid
the hydraulics on my snake I thought about this alot. I finally decided
on DOT4 for several reasons. DOT5 has a reputation for being hard to
bleed, perhaps because tiny air bubbles in it tend to cling to interior
surfaces. For whatever reason, more than one person has told me that
they had trouble bleeding their systems when they changed to DOT5. The
mechanic friend I mentioned above also told me he felt that DOT5 tended
to be spongier than glycol based fluid, especially when it was hot. But
what really clinched it for me was when an acquaintance here at work
switched the brake fluid in the two (US built) cars he owned from DOT3
to DOT5 and experienced brake failure on both cars shortly afterwards.
It could have been a coincidence or perhaps mixing the fluids caused a
problem. It's virtually impossible to flush the old fluid from the
system without disassembling every piece, including the lines, and
cleaning everything separtately.
My plan is to flush the fluid every couple of years. In a damper
climate like Georgia's I would do this once per year. With a pressure
bleeding tool like an EEzi-Bleed this is a fairly painless operation.
>A hint to others buying parts for this process. Buy new clevis pins
>when you're ordering parts. I didn't. Mine are nicely worn and now
>I'll have to put in one of those agrivating little orders unless I
>can get them locally (probably can, but still an extra hassle).
You can buy clevis pins at most hardware stores. You probably want
5/16" diameter. I bought some universal clevis pins and cut them to the
correct length. You should be able to buy them at a Brit car parts
place too. Take your old ones with you so they can be matched up.
Roland Dudley
cobra@hpcdcsn.cdc.hp.com
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