Yeah, if your water pump fails, then you will not be circulating coolant through it's passages, and in turn, you would probably over heat pretty quickly.

Now, the water pump isn't something that I would think will fail too easily, as I am pretty sure it is belt driven, but it could bind up or something like that I suppose over time.

Basically, the train of thought is that if you go in that deep, you might as well change all that stuff while you are there for prosperity's sake. Not to mention, the VX manual call for changing this at 100k I think.

Bart