ok had the same problem, my slaves continue to die after like 6 months, more than likely u have air in your system also, when u installed the master did u readjust the petal? check all of your lines one of mine had a small leak and this effected the clutch alot AKA when petal was pushed in the fluid would come out and when let go of a small amount of air would enter the system. causing my clutch petal to get stuck sometimes 1/2 way or it would fly to the floor and not return.
this problem is more than likely in your slave, replace or check to see if it is engaging,
another question is when you pump the petal alot does it start to engage?
to see if you have air in your lines pump the crap out of the petal and if it starts to work then you have AIR. the air from pumping the petal builds up in the slave.
that might help if not, explain to us a more indepth problem?