DC motor guys?

[WaterH]

I’m working on a golf cart. I pulled the motor and found the brushes were crammed full of mud/sand. They were completely locked in place. There’s big springs behind them, but they could not move the brushes. There are 8 brushes in there and I got all but 2 out. Those two broke into pieces. The other brushes cleaned up nicely and I cleaned the guides out so they slide free. I cleaned the armichure on the lathe and it looks great. The brushes have at least 3/4” to ware before they would need replacing. (They basically look like they have no ware) The brushes come in sets of 4. I ordered one set and plan to use them and the best four of the old ones.

Is this stupid? Should I replace all 8?

These have a curve surface where they rub on the armichure. I dont know if the new brushes have that or it just wares that way. If the new ones are flat, maybe I shouldn’t mix them with the old ones?

 

[Muckin_Slusher]

I would probably replace all 8 just so they're all the same, and because they're probably cheap. On the other hand, the precurved ones might help by running the motor until the new ones wear in. Some manual somewhere probably suggests only replacing one or two at a time if you can.

Did you just spin the armature on the lathe, or did you actually take a cut? Did you clean out between the segments (gently!) ?

I would guess that it'll be totally fine and wear itself in if you mix old/new. Maybe just don't give her all the beans right off the hop, instead break them in over a few short rides.

 

[WaterH]

I just used fine sand paper on the armichure. Then schotchbrite. It wasn’t in bad shape.

 

[PAToyota]

For me it would mostly depend on how hard it is to get in there. Chances are I'd still do all eight at once because no matter how much I said I'd go back and do the other four, it would be years before I got back around to it.