So getting my engine all back together after a complete rebuild, I went to bleed the air from the radiator and the top of the bleed screw broke off. It appears to have broke in the middle of the screw, which is a little baffling. I think I can get the remainder out without much work, though no clue were to source a replacement. Messing with my thread dies with portion of the screw that came out, seems to be a 12-24 thread (or at least as close to it as I can tell), though my be metric since the hex part seems to be. The parts manual appears to show a petcock valve rather than a bleed screw. I'm curious if anyone else has a radiator with a bleed screw (small brass screw with a hole through the center)?