I'm no expert either on how what Jerry recommended works all I know is I did it and my water pump doesn't weep anymore. What you recommended stpltn250r is a great suggestion and I think something that should be checked while you have it apart and performed if needed but replacing the mechanical seal isn't necessary in all cases I don't believe. Like I said before I'm far from an expert just sharing what I learned that fixed my problem and didn't cost me anything to try.