One other subtlety is the fact that the plate, where the either the ballast valve or the cap screw goes, does not have an entirely perpendicular machined surface. The seat on my pump is just barely milled into the unfinished casting edge. Makes it a little iffy as to a good seal. I got better pressures with the new O ring, which incidentally is apparently close to 11 mm OD,7mm ID,x2 mm thickness. I tried a 7/16 OD x 3/32 thk and it was too thick. There might be a closer match, but the metric size seemed to fit nicely.
Thanks for the tip on the gaskets. The copper ones seem a bit thick.
Dave Cooper
Created on Sunday, May 20, 2001 2:01 AM EDT by David Cooper