I just replaced the spider gasket on my Pentair SM20-2 multi-port valve. Everything seemed to go pretty well, but after tightening the valve cover screws, the handle is loose. It's like the new gasket is thicker than the original, which is keeping the valve spring from expanding fully. There is some leakage in the valve since the pump loses prime after being off for a while, and trace of DE in the pool.
Is is possible the pool store sold me the wrong gasket, or is this likely operator error?
thanks for any advice.