From: Barry Lovelock
Date: 11 Aug 2002
Time: 22:13:09
Remote Name: 213.122.117.4
Did you rebuild the pump with NEW springs? I hope so, if not do it! Also, hand-grind in the vanes on a glass plate with 800-1200 wet and dry. This takes skill to keep them flat but curved as original and a good apprenticeship helps!
Re-face also the brass/bronze end plate to flat and smooth and of course make sure the vanes are flat end down and vitally the gasket is between the pump and block and not the aforementioned plate. The gauge may be sticky, but cavitation is more likely due to poor oil pick-up by reason of one of the items mentioned having been neglected.
When I re-build an engine I spend a whole day, at least, removing all the oilway plugs and using wire pull-throughs in the crankcase. The crankshaft can take a day to get clear and I always do it finally in the kitchen sink, with a hot solution of strong Fairy Liquid until the oilways run clear.
As mentioned, the ball valve and spring must be ok.
A bit of a lecture!
Hope this helps.