Anybody replaced the alternator brushes?

[hobie237]

My alternators are doing fine (had them checked by a local battery/alternator/starter shop that rebuilds them and whatnot), but I was shown that they have 25-30% of the brushes left. Bearings and whatnot seem to be OK. They want $100 each for the rebuilds, which isn't really necessary. I see that "repair kits" list in the $10-$20 range, and I figured I could just go in and do it all myself.

I assume that the bearings need to be pressed in- correct? That's fine, it's not like they need to be replaced anyway, and I may be able to bum a press to get it done.

Anyway, does anybody know the correct brushes? I know they're the same as the civilian alternators when it comes to the guts (aside from the isolated ground), but the parts for a civilian truck come up as either 78 amp or 108 amp, nothing for 100 amp. Anybody got a part number?

Any tricks or whatnot I should know?

 

[hobie237]

Nobody?

 

[mangus580]

Dont forget to pull the 'paper clip' out!!

If you are just replacing brushes, you wont need to mess with any bearings. Just take your time disassembling it, and putting it back together.

If you are still looking for the parts, just go to the place that would do the rebuild. They will usually sell you the parts for them as well.

 

[beaubeau]

If it is working, leave it alone! If you have 20% or so brushes left, that can last another 5 years. Don;t wory about it. Good luck Phil

 

[hobie237]

I'm planning to put on a pretty sizable inverter pretty soon, so I'd rather have the alternators in better condition than worse. I'm not in a huge rush, but I'll have some time in December and January, so I'd rather do it rather than wait until they crap out.

 

[jbolty]

Not sure if yours are the same but the alternators on my 1986 M1031 are actually a Delco 27SI. The parts are very available but if you go to the local parts store with make and model and year of truck they will never find the exact match.

I just replaced a diode set and the cross reference for the part was from an old cadillac.

 

[devilman96]

I'm planning to put on a pretty sizable inverter pretty soon, so I'd rather have the alternators in better condition than worse.

Forget brushes... You better get some high output alternators, those poor things are only rated for 80 -100 amps.