I have a Hayward Northstar 4000 pre 2008 series pool pump. We replaced the pump a few years back but put it in the old housing since it was in relatively good shape still. Now have a leak around the union connector on top of the pump. There appears to be a small crack in the union connector (not the housing). Can not find this unthreaded part anywhere. SPX4000UNPACK1. The new part to replace this on after 2008 pumps is threaded and does not fit my pump. (SPX4000UNKIT). Has anyone else had a similar problem and how did you resolve it? Thanks!