If the threads on the bulk head fitting (black) and the bushing (white with external and internal threads) are good. Then you need to take the joint apart and put pipe dope or PTFE tape on the threads before screwing back in. That will take care of leaking from threads.
Bigger problem at this point is remaking the 90deg fitting with the threaded fittings. Doesn't look like you ave enough room to put a coupling. There are a couple of options:
1) use a long threaded nipple directly from bushing to a threaded 90
2) Dig down deep enough to flex the pipe, cut below existing 90. use new fittings from bushing to 90. Then use coupling to reattach to existing pipe.
3) Break 90 on the spine. Peel hub off vertical pipe. Then redo everything from bushing. If you haven't done this before, probably best left to a plumber.
When I removed the black spacer/nut I found the source of the leak. A few holes. I picked up a new SP1408, and have drained the pool down.
Do you think it may be possible to unscrew the existing hayward return in the wall leaving all the existing pvc, and then screw in the new SP1408? I imagine not since it's a scalloped hole and I'd need to flex the pipe toward the hole by 1/2-3/4".
In your second example, assuming I can flex everything enough to get the coupling in below the new 90, Do I glue both ends at once ... Then press and 1/4 turn both at the same time?
Or what about this, Coupling below 90, new 90, new pipe toward wall. Glue all that, then tighten up the threaded coupling less 1/4 turn. Then final step would be putting new return & threaded coupling (glued at this point) into the short pvc while performing a 1/4 turn as it comes together?
I got it. There was enough flex between the pvc and being able to pull the wall fitting into the stretch of the pool liner that it was pretty easy.
On a side note for anyone with this type of leak, I should have tried putting epoxy inside the accessible gaps from the pool side. Now that I see where the leak was I think that would have been a good fix assuming epoxy lasts a while.