Thanks Brian, but checked the brushes, there's about still 25mm of carbon poking out past the housings on the brushes, when I popped them out, so don't think it's that.
Alan, May 2010
Alan,
It could be the carbon brushes in the motor that need to be renewed, checkout this website www.apart4u.co.uk, on how to carry out this type of repair. It shows you a short vieo clip.