Miele Brushes Worn Down One Side Again

[malcs]

I replaced my brushes on a Miele W504 washing machine about a year ago, after I go the 'rinses' light flashing error, and found brushes were worn down badly on one side.
Got the same warning last week, and inspected brushes again, and exactly same problem.
Anyone know, why they wear down on one side? I have seen this reported by others, so just wondering if this is a known design fault?
Just a shame Miele don't fit proper brushless induction motors to the full range of models, as this is the only thing letting the brand name down in my opinion.

 

[Burnerman]

I expect the worn brush is on the side of the motor which is pulled tight by the belt......slight distortion or minute bearing wear being the cause.
John

 

[RichardMNZ]

When you change the brushes, check the commutator is perfectly round and smooth.
Did they tick when the drum rotated in one particular direction?
Was it the right brush (When viewed from the front) that wore more quickly?