We bought a house in April and the pool hadn't been opened so I discovered a slow leak where the filter coupler adapter meets the pump's out port. I removed the adapter used the best PVC/ABS thread goop possible and it still leaked. Less but still. Today I opened it again, assuming that if the threads are damaged, then like our pool guy wants, replace the whole pump. Not without a fight! I was/am prepared to use J-B Plastic Weld Syringe to permanently fuse the two together and fill any cross threads. BUT in getting ready for this surgery, when I went in to clean the pump threads I discover a chunk of ABS missing and 3 pretty deep lines coming from the hole to the outside edge. I can't believe I got it down to one drip per every few seconds. 

My question is how to best do this.

1. Am I on the right path by using ABS/PVC plastic bond to fuse the adapter into the pump permanently? This is way beyond teflon or any super thread tape IMHO.

2, I'm sure filling the damaged indents would be key unless I'm over thinking and just putting this intense bond agent in all the PVC adapter threads and inserting will naturall block all out bound leaks?

3. How to fill: I'm thinking I could first put the bond agent into the damaged threads, since it starts to cure in just 5 minutes, as it gets just a little firm so the goop holds its place, then. I would screw in the adapter with the same JB goop on its threads. As a second thought, JB makes a plastic putty that might be better since it holds its place, but I'm concerned whether it will screw up the thread path and will it bond or reject the liquid bond. Mixing scares me. 

4. The adapter will become part of the pump which connects to the filter as you all know with a union, so I'll still be able to remove the pump or filter from the system for repair or replacement.