I have a Culligan Gold Series Gen 2 water softener. There is a leak at the screw knob on the bypass valve assembly. I have looked at the culligan manual which shows breakdown on everything but the valve. Can it be disabled to most likely replace a worn o-ring? It looks like the end cap should unscrew. I don't want to break the assembly since it only leaks if opened fully. I assume it'd be $150 or more for a replacement if available.