Water pump - '95 525 w 40k miles

[WCFJ63C@xxxxxxxxxxx ( DEAN KNUTSON)]

Marc..please list the "for sure" symptoms of water pump failure. I'm 
watching mine closely...I'm hearing grinding noises near the fan and 
now I have a very small puddle of coolant on the garage floor each 
night.  So far no smell or leaks apparent in the engine compartment.  
But I sure don't want to happen and get stranded on the road.  When 
to know for sure and when to do the preventative repair?  ps- did the 
'95 525's have the plastic impellers?  Thx, Dean

------------------------------