So I picked up my third master cylinder at Napa a short time ago ( this time a rebuilt), because the last two New ones, would leak past the piston on the bench bleed. Much to my surprise I find , (for the first time) in the box, an ATTENTION notice that states .."When bench bleeding this master cylinder, do not depress the piston more than one inch. Doing so will give the appearance of the unit leaking". This information did not appear in the last two cylinders that I purchased. This is a single type reservoir system, non Mopar, and quite frankly is a re- education for me. I must have forgotten the one inch rule! So in the spirit of the idea behind this site ,I am passing this on because it gives you one more thing to consider , or one more question to ask, if you ever run into the same problem bench bleeding an old style single master.
I intend to follow this guidance to see if the third time is a charm!
Thunder