check the shaft with the brushes on it under where the belt fits it and look for grove if there replace shaft with brushes and check motor shaft to see colour should be silver if it is black belt is slipping on shaft happens with cat and dog fur shaft must be cean at all times fault with vacuum
ray vivian
December 2006
additional make sure the motor shaft turns freely with the belt off.
paul
October 2006
replace the belt. make sure the motor is getting air to cool it. the bad news is the motor possibly failing.