How to repair fix an electric motor - replace carbon brushes

Often motors only need a cheap $2 part to be working as good as new. Carbon brushes can wear out and they are replaceable. The ones I used cost only $1.29 for the pair. And that included shipping.

Carbon Brushes on eBay: http://rover.ebay.com/rover/1/711-53200-19255-0/1?icep_id=114&ipn=icep&toolid=20004&campid=5337979816&mpre=http%3A%2F%2Fwww.ebay.com%2Fsch%2Fi.html%3F%26_from%3DR40%26_trksid%3Dp2323012.m570.l1313.TR12.TRC2.A0.H0.Xcarbon%2520brushes.TRS0%26_nkw%3Dcarbon%2520brushes