water pump 1275

I just had my alternator croak on an early morning run to a local rugby match.
When removing the alternator the part of the water pumpt casting that the alt.
mounts to fell off.  It's been broken for quite some time by the amount of
grease in it.  I'm going to replace the water pump, right?  Or does the fact
that it's been running fine as broken mean I just replace the alt.?  I think the
former, but thought I'd check wid youse guys.

Geoff Branch '74 Meejit  (can't spell name or Meejit)