1980 R65, It sat for 10 years and I am trying to rebuild the ATE front brake "round" Master Cylinder. The inside looks rust free but there was some junk floating in old brake fluid before I cleaned it out. I installed the Magura rebuild kit as instructed but still get no pressure when pumping brake. No leaks, I notice 2 holes in the bottom of the master cylinder. One appears open and the other does not. I would appreciate any suggestions. Thanks