Clutch Slave Cylinder

[bpm4x4]

I have a tranny/ t-case setup out of a 96 XJ (external slave) and when I put in the slave cylinder and hooked it up, it blew apart (the pedal was hard to push down to the floor) after I really pushed on it. I have to pull out the tranny again to get some of the pieces that fell down in the bellhousing, and wonder if there is anything I should check while I have it out. The slave was not new, but the clutch was so I will look for anything obvious. I just don't think it should have been that hard to push.

 

Thanks in advance.