Find out if the bolt extends into a source of coolant.Should be information somewhere or talk to a dealer. If not new gasket and check the housing for cracks.

If the bolt extends into a coolant area removal of the bolt and the coolant will flow out pretty good from the hole.If the bolt hole where a lot deeper than the bolt I would also expect that.

Although since you may not have owned the vehicles since new. May or may not be the original water pump. That is always an issue with used vehicles purchased with no records.

That is a fair amount of millage on the water pump if it is the original. If I felt it had to be removed I would replace it. More modern engines are more demanding to risk anything. This is a cheapie in the real world of modern costs.