Hydraulic Throwout Bearing and Master Cylinder Question

[Dave Haller]

I have a Ram hydraulic throwout bearing installed with a CNC 1" bore master cylinder. At Speedweek the clutch pedal kept bleeding down with pressure applied on the clutch pedal. When we got the roadster home we tore down the master cylinder and found a torn rubber cup. The cylindre bore had a burr in it so we honed it out and rebuilt it. We put it all back together but are having problems getting it to work now. We keep trying to bleed it, air comes out but the pedal won't return to full stroke. We tried stretching the spring to get more tension but that didn't work. The piston in the bore comes back to about a half inch of full stroke then won't return the rest of the way. Anyone got any suggestions. What are we missing trying to bleed it?
Thanks,
Dave Haller #93

[Stainless1]

Look at the seal cup you installed.  We had a similar problem and needed to turn the pusher down a little because the seal from NAPA was different than the original and increased the friction of the seal in the bore.  We put a 45 on the edge of the pusher to match the seal and then the spring would return properly.