If you do not change the fluid in the clutch system often, the components will not last long at all. The heat from the headers cooks the fluid in the MC and line. When I say often, I mean
at least every 6 months. even after 6 months the fluid is nasty. You should suck the old fluid out of the MC and replace it with new. Then bleed from the slave until the fluid looks good. This usually takes me filling up the MC at least 5 times.
BTW, when bleeding don't go over 3 pumps before refilling the MC.
Since doing this my slave has lasted just fine. It is a less then dependable set up though.
I can't imagine any other slave lasting longer with fluid that is bad. I'd like to convert to a cable set up.