Ok so I put a new water pump on my 5.0 4 months ago and its weeping once again... Wtf ?

 

I assume you used fresh coolant when you filled the system back up. There could be something in the coolant that ate away at the inner seal. But if you don't have problems with other gaskets (head, intake), that wouldn't (shouldn't) be the case. Exhaust gases in the coolant could be a possibility for something like that. There is always the chance that the replacement part was defective.

 

Well it was a refurb Haha