how can i stop my float from rattling?

I recently cleaned the float of my condenser dryer (indesit is70cuk), but now it seems to rattle. It was a bit greasy before I cleaned it and now my theory is that was what stopped the rattling previously. Could this be? If so what grease should I use and where can I get it from? If this is unlikely to be the problem, how do I go about diagnosing the problem and fixing it or would I be best to buy a new pump alltogether?