1999 Volvo GSI. How often do circulating pumps or their bearing go bad? My problem is that my belt is producing a ton of dust. Everything seems fine, but there is a slight movement in the circulating pump pulley (very slight) and you can hear it if you spin it with the belt off . Not sure if this is normal, or if I am being too sensitive and there is another problem. Last summer the raw water pump was leaking and shot water around the engine for a couple of days, but was replaced.