Is the motor done or is it the brushes? Hotpoint aquarius 1200 spin wma44s?

Our machine runs fills and will empty however it runs and turns for mainly only for a few minutes but as it does this there is a lot of blue sparking -like welding from the brushes. I have taken the brushes out and removed the motor and cleaned all the carbon dust out and checked the brushes they are unevenly worn but have plenty life in them. I put it all back togther but it is still the same. Any suggestions?