Since you called it a bridge rectifier, I assume you know what that is and how to test it. And yes it is a bridge rectifier.
Water pump: If it still has the original pump, it is the old aluminum housing. And I strongly advise replacing it with a complete new pump kit with plastic housing/stainless liner. We had a lot of problems (fried motors) with the aluminum one. Of course if it already has the plastic pump, all you need is a new impeller.
