I have a 5+ years old GE GXSF30V softener that the output connecting to the unit had a small leak by where the locking clip is. This is the right part and fit perfectly without any leaks. Naturally, for this repair you would think it's the o-ring that is leaking, but it's not the case. You MUST shut off the water main to relieve the line pressure in order to remove the locking clips. With a mid size flat screw driver to pick/remove the clips carefully. O-ring replacement did not address the root cause for me. The whole by-pass valve must be replaced to stop the leak, and it did. My research tells me many have the same hairline crack that is invisible. Mine is on the outlet side or left side when you are in front of the softener. The crack is on the inside/top, so small and invisible, but it can leak a few gallons a day to your brine tank. If I've known better, then I will skip the O-ring, go ahead with this part and be done. But your process of elimination may still involve the o-ring replacement as your first step. You have to pick your battle.

Had a leak in my water softener and this fixed it.

The media could not be loaded. Had a constant drip between the diverter and the valve body "inbound", and it was slowly filling up the salt storage tank. Rebuilt the venturi, thinking it wasn't pulling up brine through the recharge cycle. Nope. Replaced O-rings. Nope. People are correct. Diverter can develop an invisible crack! This did the trick. It comes with two O-rings installed, but it's a good idea to replace the O-rings on the two adapters that connect to the supply side of the diverter (circled in red). Use Soft Water Supply's 4 Pack 7170288 O-Rings - 7337571 Kit plus 1 gram silicone o-ring lubricant ASIN B07MZFRWWB. They are perfect, unlike some knock offs that don't fit. To get the holding clips off, (before disassembly!!!) SWITCH OFF HOME WATER SUPPLY, open a faucet to drain pipes. This will depressurize the brine tank and release tension on the holding clips on both sides of the diverter. Brine tank will not depressurize if diverter is on bypass.

This fixed the water leak problem where the tank was filling up with water. We tried to replace the O-rings and that did not stop the leak. We could not find any leaks but ended up buying this valve assembly as a last resort. Once installed the bypass handle moves freely and the leak stopped completely. Upon closer inspection of the old part there was a hairline crack visible. I have circled this in the photos in red and there are pictures of it without the red marks so you can see how difficult it might be to see it with the part installed. I hope this helps someone who has the same issue with water filling up the salt tank.

Part was perfect fit for my Kenmore 350 water softener. Make sure all water pressure is drained off before removing old part. The retaining clips will then be easy to remove. This new part fit perfectly and no leak any more.