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Parts for Whirlpool KSM90 Mixer - AppliancePartsPros.com
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I wonder if this is indicative of a worse problem than worn brushes?
And does anyone know any tricks to get them out or will I be pulling the motor out?
Place the unit on it's side and tap it, perhaps gravity will help the brush fall out. Also while on it's side install a beater and move it. This may move the armature just enough to release the brush.
If you have a small/fine set of needle nose pliers you may be able to grad the end of the brush where the spring attaches and pull it out.
Or get a small wire (paperclip) and try to move the brush a little.
You may want to remove the motor so that you can inspect it. If the brushes are worn all the way down odds are that the armature may need replacing or cleaning up with some fine emery cloth.