Looking for insight on this, and also curious if anyone has ever seen a failure quite this bad of a brand new aftermarket part.

Recently completed a timing cover and water pump replacement job on my 2003 3.0 Automatic 2WD. It was very involved and time consuming, but I got it back up and running. After idling for almost an hour with no problems, while I filled ATF and coolant to full, I took it for a test drive, and the brand new water pump broke off completely at the shaft "nose". It happened during the 4th or 5th wide open throttle pull I did. The fan fell down and twisted the belt around the shaft. I had to get it towed back.

Did I just get incredibly unlucky and installed a brand new part that happened to have a defect in the casting? Is there something else I missed that could have caused such a catastrophic failure. The actual shaft and bearings of the water pump are intact and not seized, the housing itself seems to be what failed, very dramatically.

Water pump was Murray brand, but I have a Motorcraft replacement on the way. Also replacing the fan clutch and blade, belt, tensioner and idler pulley. From what I can tell, all of the pulleys are aligned properly, and the tensioner/idler only have minuscule play (maybe a few thousandths of wiggle). They need replacing, but I don't think they were far gone enough to cause a failure this sudden.

Thank you for any thoughts on this!


Housing snapped clean off

Installed, before it exploded

 

id say just the luck of the draw