The motor on my 8512 is definately brushless. My problem was similar to above. The motor seemed like it was struggling and made this grumbling sound with the drum struggling to turn. It would spin fine but just struggled on the wash cycle.
I fixed it by replacing a capacitor located by lifting off the top lid and at the back right hand side of the machine. It has two spade connectors supplying it and is rated to 20.
It comes out by loosening the nut. I just took it to my local spares shop and got a new one for about £18.
Kenny
March 2014