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View Full Version : Worn generator brushes after 1,800 miles



NC_Mule
11-09-2012, 12:06 PM
Rebuilt my generator(brushes, springs, bushing, bearing) 1,800 miles ago and it has been trouble free since. This morning my charge light came on. Tested the output and I'm getting max 1 volt. Pulled the generator apart and found worn bushings. The lead on the right (the thicker brush of the two) poped out of the brush itself . Any ideas why they wore out so fast? The thin one looks about how the old ones looked before I changed them and they were in service for a long time.
7298

o2batsea
11-09-2012, 12:39 PM
Did you use any sandpaper to clean the commutator? That's the only thing I can think of, other than it just being a bad brush, for it to go bad so soon.
Commutator has to be really shiny and polished. Worst case, you take the rotor to an armature shop and have them run the thing thru the lathe real lightly to clean up and parallel the commo.
You did "flash" it when you put it back in, yes?

I Leak Oil
11-09-2012, 01:39 PM
Worn bushings? Hmmm. Usually a sign of an overtightened V belt. Did you lube them when putting it back together?

NC_Mule
11-09-2012, 01:55 PM
Did you use any sandpaper to clean the commutator? That's the only thing I can think of, other than it just being a bad brush, for it to go bad so soon.
Commutator has to be really shiny and polished. Worst case, you take the rotor to an armature shop and have them run the thing thru the lathe real lightly to clean up and parallel the commo.
You did "flash" it when you put it back in, yes?

Rotor is on a lathe at the armature shop as we speak. What do you mean by "flash it"?
I leak oil, I didn't lube the brushes...what should I use. A little general purpose grease so they slide?

I Leak Oil
11-09-2012, 02:11 PM
Don't use grease on the brushes. I'm referring to the worn bushing that you spoke of.

NC_Mule
11-09-2012, 05:13 PM
The back bushing was replaced on the initial service 1,800 miles ago. Armature shop cleaned up the rotor and I got new brushes from him. He said the rotor had a flat spot so may be that was the problem. All is well and back together. I'll pull the generator off in 1,000 miles and see how the brushes look and if they are wearing evenly.
Thanks for the comments.
pb