[Shop-talk] Sleeving a hydraulic clutch cylinder

[tr3driver at ca.rr.com]

---- Wayne <wmc_st at xxiii.com> wrote: 
> Randall, et al:
> How do you keep an old car like that going?

It turns out that the Triumph TR series is popular enough that there are replacements available for practically everything.  And they made enough cars that most things are also available used from cars that got wrecked or rusted too badly to be worth restoring.

Other cars (and old machines) are not so fortunate, of course.  There was a story on Leno's garage of how he got a "bargain" on a 1914 Premier because it had a broken water pump housing and a replacement housing was simply not available anywhere.  (The fascinating part of that story is that they were able to create a new housing using 3D printing techniques.)

But something about the old "hand" machining techniques appeals to me.  I find it really cool to both make something and then use it.  Eventually, I hope to even branch out into doing my own castings (even though 3D printing will probably make castings obsolete by then).  Weird I know, but I enjoy it.

> Would it possibly be easier to over-bore the cylinder, and fabricate a 
> matching piston & rod assy?

A possibility, I guess, but I think there would be problems.  Before it failed, the original cylinder started wearing rapidly.  The dust seal was literally full of tiny aluminum particles from the wear.  I don't really know why that happened; perhaps there was originally a thin hardened layer that I honed through or perhaps the inner surface was weakened in some way by long exposure to contaminated brake fluid.  But since I don't know why it happened, I also don't know that it wouldn't happen again.  The brass seems to offer a sure solution; and one that could be repeated if necessary.

The seal is also custom for this application.  It might be that a standard O-ring could be made to work, but I've never seen a master cylinder that didn't use a cup-shaped seal.  Seems like there must be a reason for that.  And since seals do wear out and need to be replaced, I like the idea of being able to just stuff in a new standard seal rather than have to remember what tricks I played last time.

Randall