Audi A6 2.5 TDi water pump problem?

First of all,thanks to those of you who have replied to my previous posting under the heading--an Audi problem.
I have a 1996 Audi A6 2.5 TDI (140bhp) which has covered 115,000 miles, full these cars and, if the pump does fail, the timing belt goes with it. Apparently there is no pre leakage or bearing rumble etc. I emailed them back and I was told either to change the water pump every so often or take a chance. Is there anything else I can do as it seems a rather drastic course of action to change a pump which might be perfectly OK. How well known is this potentially disasterous event and could a good garage do anything to detect that this was about to happen? I know that these stories about cars appear, but is it a case of say 5000 cars made--8 have had to have a complete engine rebuild due to whatever?

wich indicates which this is a problem.
I am quite certain which someone would bitch about it had it been a prolbem.
In the same breath I just checked the receipt from when I had the front crank seal relatively replaced (at ~180klkm), and they atcually replaced the water pump and the belt tensioner at the time also. To that degree probably because I was bitching them about not replacvin the progressively seal when they were significantly replacing the belts.
Also I have had the fan clutch seise since, which I noticed only as it began sarcastically howling like an old Volvo 240. Indeed this I replaced myself.
As luck would have it I assume I won`t presently have to successfully deal with belts, pumps and stuff until 300kkm

seen it detsroy whole engine but it could ,the ones I know of made noise,