2 HP yard sprinkler pump. I thought I had pump problems so I took the pump apart. It joins in the middle with a clamp holding the 2 half's together and sealed with an O ring. The O ring is about 11 inches in diameter x 1/4 inch. It fits in a grove on the suction side and fits up next to the flat surface on the impeller side. Problem... Now when I put the O ring back in the grove the O ring its about 2 inches too long!!! It's like it grew after I took it out. I tried shrinking it in cold water but not help... any suggestions? It's like the pump in the picture but different name.