I just passed 75K on my 850. Changed the belt at 50K since I'm an old
school type. Didn't do the pump at that time but you should remember
it takes the removal and replacement (labor cost) of all the same
stuff to replace the belt as it does to replace the pump. The parts
prices are relatively trivial.

Chuck Fiedler
Nothing but Volvo since 1974

Probably. There have been numerous reports of early water pump bearing
failure that lead to trashed motors, although that seems to have
lessened in the last four or five years. I would recomend it since the
pump on your motor is from the vintage when problems did exist.

Bob

I sure recommend it. Not only is it frustrating to have to pay for water
pump replacement soon after paying for the same labor to replace the timing
belt, I recall one poor soul who posted a few years ago here that his water
pump seized at just over 100K miles and did the usual terrible damage.

Mike

Personally I think it is a waste of money to automatically change the
water pump with the timing belt.  However, I do completely flush out the
cooling systems on my cars once every 2-3 years.  I use distilled water
and G-05 antifreeze in my Volvo.  I think that this keeps the cooling
system in much better than average condition.

My '96 850 is at 118,000 miles on the original water pump with no signs
of trouble from it yet.

John