Paul Delta has a replacement it's not the same but it will work for you, as for what goes wrong with them as long as the motor runs the only other problem is the tiny impeller inside the pump body it's made out of rubber and over time some of the vanes break off, I think there are either 6 or 8 vanes on it, once they go the pump looses effiency and slowly stops pumping liquid, I have taken other pumps apart on many scrapped cars and as yet have not found a similair impeller that will work, if you want to stay original then you need to find someone who is willing to sell a working one.
