If the pump came with a pully already on it check for size differences between the old one and the new one..
If You installed the pully yourself which is usual.. then the culpret is prolly typing questions..
I have seen all sorts of wrong belt installation from many different guys... However I have never seen a tensioner go bad when the belt was off of it.
Big Jim <img src="/forums/images/graemlins/pfft.gif" alt="" />


professional bovine relocation specialist