Could the problem be air lock, since I drained the pit? If so, how can I get rid of the air lock?
The piece of pipe below the gate valve and check valve seems to have a hand-turnable section, but it seems like there is pvc epoxy around that connection (which is why I can't turn it). Is it common to epoxy this part? Could I loosen it with a pipe wrench?
How would I go about installing a new check valve and pipe to connect to the pump? Where the 2" pvc sits in the pump, how is that connection made? (do I need a special fitting and/or epoxy?