Master cylinder drip

[Impalaguru]

I rebuilt the master cylinder for my 63 and while I was in the process of bench bleeding it I noticed that it would drip out the back when I would release the piston. Somehow there is some fluid passing by the piston. Anyone have any ideas on what to do? Or what I did wrong?
Ross

 

[raymar58409]

I would say you may have cut either the of the rubber parts or the bore is pitted. Bout the only things I have seen cause this.
Ray