Clutch Problem

[Aervine]

Hello all. I'm having a strange clutch problem, and I posted this on another forum and haven't gotten an answer really. After driving for a while my clutch will start to slip I then pull over and have someone push the clutch down and bleed it then get back in and start to drive and it'll be fine. My hypothesis of the problem is that it's an S14 car, transmission, master and slave cylinder, but the pedal is from an s13(because I did the auto to manual swap.) I bled the lines for a long time from normal bleeding and vacuum bleeding so it *shouldn't* be that, I mean I really put alot of fluid through those lines. So anyway would the s13 pedal cause me to build up pressure in the slave cylinder and when I bleed it it's fine?