Update - Main outer drum leak repaired using Milliput.
However during fast spin, on each revolution, there is a knocking noise, which gets extremely loud at 1200 rpm, like a machine gun going off ! 
Is it possible that there is some 'alien' object in between the inner and outer drums ? e.g. a coin ? 
If so, how can access be gained to remove such an item ?
                
 Glenn
                
 February 2010