Water pump bearing has recently developed a rattle (when hot) that becomes a low-pitch whine around 1200 RPMs. Never nursed one along to failure before (always changed the pump at first sign of bearing noise), but since this motor is due for swap (soon, I hope), I'm just wondering what to expect (I'm under the impression that bad bearings can still run OK for quite a long time)? Aside from leaking, what kind of catastrophe might total failure/seizure entail? Worth the risk?

6 VOLTS/POS. GRD. NW INDIANA