I have a Purex Triton SM-20-2 (27-3207) Multiport valve that leaks in the filter position. I've read many posts refering to other Brands but not mine. I have no manuals or diagrams of ths valve. Is it safe to leave the hande in the filter position and remove the screws to access the gaskets after draining the DE filter? Also will the gasket have to be glued into position? Thanks in advance.