I have found that if I disconnect the multi-plug from the motor, it does not trip the RCD.
If I just remove the earth lead from the motor (with the multi plug still connected) everything seems to work fine.
I believe that something is going to earth within the motor.
I have fitted new brushes and tried it without the speed detect device( at least I assume thats what it is) connected to the end of the spindle.
Can anybody confirm this? Is it a common fault? Would fitting a new motor cure this problem? Or would I be wiser to buy a new washing machine?