I own a different servis machine, but it looks the same.
Could be a leak from the filter cap on the bottom right of the machine, if you open the flap, you should be able to either see or feel if it's wet. If that's the case this unscrews and there is an o ring in there that may need replacing.
Otherwise there is a hose that leads from the drum to the waterpump or the outlet hose from the water pump possibly one of them is leaking and may need replacing or if you feel movement on these hoses at the connections, maybe they just need to be tightened up.
Mark, January 2010