I have an old Hayward sand filter with the Vari Flow Valve model SP117 that came with the house I recently purchased. I haven't had a whole lot of experience with a Sand Filter or Multi Port/Vari Flow valve and want a second opinion before I go tearing into it. Every time as of late after I backwash & rinse, it takes a while and several times of rotating the valve around to stop the discharge of water out the back wash pipe. I have been turning off the pump, switching from Filter to Backwash, letting it run until clear then turn off the pump, switch to rinse for 30 seconds or so, turn off the pump and switch back to filter. The discharge isn't under as much pressure as when the valve is on backwash however I'd guess it as about half the flow. I can even get it down to a trickle but it always takes some finagling to get it to stop. Sometimes as much as 20 minutes worth of rotating the valve around 180 degrees. I've tried holding my tongue on the left and right side of my mouth, standing on one foot, crossing my fingers etc. but just can't seem to make a smooth transition from Rinse to Filter. Is this a sign that the spider gasket needs replacing?