For some time now I have been trying to resolve an issue with my GE water
softener in where the brine tank fills up until it overflows. I examined the
venturi, but that was only slightly dirty and the problem persisted
afterwards. I started a regeneration cycle and I didn't notice anything
unusual until the brine draw cycle. I have noticed that there is this rubber
valve cover that seems to drop down onto the top of the valve and then stop
the brine draw. It looks as though it should be attached to the bottom of
the float, but I'm not sure. I have ordered a replacement assembly for the
unit as I wasn't able to firmly reattach the rubber valve cover.

I've read others replacing their control valve with a 3rd party assembly.
I'd be interested in that as mine seems to be inefficient to begin with.