How do the brushes on my hoover steam vac work (or not work)?

I have one like that. There is a so called fan blade that spins from the forced air that flows across it and as it turns it turns plastic gears that propel the brushes. This fan blade has a shaft on it that goes thru a copper or brass bushing (not bearings) When moisture gets into this bushing it has a habit of corroding and will freeze the shaft in the bushing and stops the fan from moving which in turn stops the brushes from turning. It is an easy tear down and fix if you have a little knowledge on disassembly.

df
June 2008