Just when I thought I was done fixing the leaks I find this leak and I can't figure out how to stop it. From what I can see it's happening at the shaft seal. Both seal parts are brand new. The piece that inserts into the back of the wet end (attaches to the motor) was caulked in with silicone, just like the original. The other piece is just inserted into the impeller.
After replacing all the O-rings and seals, I assembled the pump and bench tested it by filling up the wet end. There was no leakage at the suction cover but there was a steady drip from the back, where the motor attaches to the wet end.
I took it apart and applied silicone grease to the shaft seals and tested it again. No change.
One thing in the back of my mind is I took apart the motor on that pump to make sure the bearings were good. They were and I put it back together. But when I did, I couldn't get the capacitor housing to line up dead center on top like it is for the other pump. It's off maybe two degrees or so. The rotor spins freely. The motor housing seats flush with the mounting end. So I doubt the shaft is misaligned. And I can't see how the housing rotation can affect the alignment so long as everything seats flush. The impeller tolerances against the back of the wet end are consistent and the impeller spins freely once everything is assembled.
I'm thinking the new shaft seal pieces might not be pressing tightly enough against each other or there is some seating flaw I can't see with the naked eye (or with magnifying glasses either.)
Should the motor shaft be greased? Should the shaft seals be greased? Is there anything I may have missed? I did everything the same to the other pump except dismantle the motor and that pump is leak free.
Any ideas?
