As you take it all apart and get ready to remove all the bolts for the water pump it's self... the one bolt on the furthest left as you straight at it is very well known to get corroded and sieze into the engine block or the pump housing and will snap off... Get yer drill n taps out just in case it does.
While yer in there ya may as well change the crank seal... ($5) the front can seal... ($5) and the timing belt and tensioner pully as well... (bout $30 for bother pending on parts supplier)
It's just piece of mind so that ya don't have to take it apart again.
Your gonna have to remove the timing belt anyways...
Kelly