Union connection at pump- how to replace?

[brew4eagle]

I had a leak at the pump union connection at the end of last season when closing, so just now getting around to fixing it since ready to open. I assume it's an o-ring (5+ years old), and I also assume it's best to just replace the whole part of the union that threads into the pump since I have it apart (1st pic attached) as it won't cost much more than new o-rings. Do I also have to replace the collar piece (2nd pic attached) that can't be readily slipped off, or is it fine to mate it to the new union piece? I assume it should be fine to use the old collar, and that's part of the convenience of these types of unions, but just want to ask the pros. Also, is thread sealant recommended or not?

 

[mknauss]

Those are what is called pump unions. They are not the same as the unions you can buy at Home Depot, Lowes, etc.

If the union half on the outlet pipe is OK, then you should be able to just replace the union half on the pump. Though you may find replacing the oring as sufficient. You can use teflon tape on the pipe threads into the pump, but not on the threads of the union.

 

[brew4eagle]

Great, thanks for the reply. The replacement pump half comes with the o-rings and is about $7, so figure that's easier (and likely cheaper) than tracking down the correct o-rings