I didn't torque mine because of the tight space and my wrench is a 1/2" drive and there is just so much space in there. Since you followed a resonable sequence, I am wondering if the gasked that came with the pump takes up enough space to leave clearance between the impeller and the motor inside. I read someplace on the board that some the gaskets are different on some of the pumps. Mine was a stiff and thick metal gasket. Other then that, the only other thing I can think of is the pumps are just c**p
