I bought a used 450 off of fleabay. Upon examination of it I noticed the rubber O ring on the seal plug was leaking. I ordered a few O-rings and that seemed to fix the lube leaking. I trie using a harder lube (with out a heater) and ended up pulling the pressure screw thru the seal plug. So I ordered a pressure screw assembly and in stalled it. I also bought a heater. Now when the lube gets up to temp it leaks around the seal plug again. Is this a common problem? It seems there isn't enough pressure to keep the seal plug imbedded in the casting. I'm to the point of inverting the casting in a vice on my mill and milling the bottom of the mounting base perfectly flat. Then add a steel plate to the base by way of tapping screw holes thru the base and counter sinking the steel plate so everything would be nice and flat to mount on top of the heater. The steel plate when, tightened up, should keep the seal plug inbeded in the casting.
Thoughts or suggestions?
Send it to Lyman?
Thanks for any help.