Seal kits - could be the "rubber". Begs the question of what type of rubber are they made from Butyl, nitrile... Some stuff breaks down quicker than other and some stuff is incompatible with the fkuid you use. Could cause things like swelling or breakdown. I ran into a problem where the kit was old. The other problem I ran into was not replacing the master and the slave at the same time. And Finally doing a poor job of flishing and cleaning our the pipies before putting it all back together. It only took one small shaving to ruin a new bore.

je