How to check the water pump is running ok.

If the bearings appear quiet and smooth, and there is no leakage from the weep hole, it should be fine.

 

If bearings are OK, the only thing that could be wrong, and this is like really, really rare, is your impeller is loose or has corroded away, and that can only be checked by removing the pump and giving it a visual inspection.

If you are chasing a cooling problem, the pump is about the last place I would look.

Doug

 

If the pump is old and you put a new belt on or re-tension the old belt, it will rapidly shorten the life of the pump. Once they age and settle in, the bearings just dont appreciate more tension. I cannot begin to recall how many water pumps I have replaced shortly after being nice and putting on new belts. I have had many, many water pumps on various engine's fail within days after a re-tension, some within hours the same day.