Just came on board today. Opening pool and having problem with locking ring. Came off easy enough but when I put cartridge in and tried to close ring stopped just before locking pins. Now ring will not turn in either direction. Sprayed with silicon spray and nothing. Used a rubber mallet (tap, tap in each direction) nothing. Leverage is not great, whole filter pump assembly is moving when I try to spin ring. Any suggestions would be greatly appreciated.