I have a Tab McBlaine slave cyl for my 94 VD. If you're familiar with the mid-year slaves, there's one groove the Brits didn't get quite right, and the kits sold by TRE, etc, have a special oversized one to compensate.
Now Tab made his to use standard o-rings, I believe three different sizes. Two are known, the other he doesn't remember and despite having the drawings, I don't have enough o-ring talent to guess the other size.
Prepping for this season and decided to break my "if it ain't broke, don't fix it" rule and swap out the slave, which had been in there for many years. It had gotten to the point where it was a good idea to get some heat in the oil before stepping on the clutch pedaI. had a VD slave in my spares box already loaded and ready to go.
So I was taking apart Tab's device, and decided to throw it in my ultrasonic cleaner. Its filled with a mix of ATF and mineral spirits. After a couple of hours I took it out and the external o-rings had swelled to the point where they almost fell off. But the internal ones - well they didn't appear flattened anymore and were snug in their grooves.
So I put the thing back together and it was pretty much like putting in new o-rings.
So, if you find yourself a couple of days out from a race, or at the track with a split car and failed slave cylinder, soak the o-rings in some ATF and thinner for a couple of hours. Be really careful with the thin ones on the outside so they don't get too big.
