After backwashing, I am getting leaking from the discharge hose when I put the valve handle back in the filter position. Have changed the spider gasket, but still leaking. What would be the next step to try to stop this.... new multi-port valve?
First try pushing the handle down and spinning the valve a couple of times in the same direction with the pump off. It may clear some debris that has gotten caught in the gasket. As a practice, if you start using your system by turning the handle clockwise, never go counter-clockwise to return to a position. It is always best to turn them the same direction. That was instructions from a long ago filter school (I believe Hayward).