Hey thanks for looking. I'm swining around my mooring this afternoon and ran into yet another problem. I have a 26' aft cabin welcraft powered by a fresh water cooled 5.7 mercruiser. If I run the boat everything is fine but if it sits for a while the pump locks up and the belt squeals.
Now this is the important part, if I drop the serpentine belt I can spin the pump in reverse with relative ease. This has happened several times and what seems to be happening is the vanes in the impeller are flipping over. If I really struggle I can turn the pump in the correct direction and it will work again. The pump was rebuilt by the previous owner and I took it apart when it did this the first time and everything looks fine. I reasembled the pump the first time and it worked for a while on the trailer. Then it happened three more times each time after sitting for a while. It almost seems like the impeller is in backwards but everything I read on it doesn't seem to have a right way and a wrong way.