^^ Agreed with that dude. I used to do phone professional phone repair for a living, arguably the best technician in town, but I would still tell people there is no guarantee that their phone would be water-resistant after replacing any parts, even on something like a Casio GzOne Commando that has rubber gaskets everywhere.
But to be fair to the original poster, you shouldn't just think of your phone (before you break it) as a phone that can survive in the rain, since Samsung advertises it as being able to be completely submerged in a fish tank or have champagne poured all over it. You should be able to keep it submerged under 1 meter of water, for 30 minutes (again, before you break it), because Samsung guarantees that you can.