Bruinpilot

Same problem as in the previous thread, brake and battery light on. I pulled the alternator and wanted to attempt changing the brushes. I've never done it before and the worse thing that happens is I screw up and got to get a new alternator. I bought the whole Nippon denso brush holder assembly on ebay for like 8 bucks. I got out the old brushes and the lower one was sticking, gummed up and looked worn beyond limits, so probably that was it. However, when I removed the old assembly, it cracked up. No big deal. Also the rubber cap that goes over the brush holder tore on one side when I pulled it up to get the old brush unit out. After installing the new unit I got this rubber thing back on somewhat snugly, but it is a little warped and now one side is torn. Does any one know if this will effect the operation of the alternator?

Thanks for the info. Also, I have never opened up an alternator; it is a little greasy in there. Is this normal? The thing was actually working most of the time before I pulled it anyways. The batt and brake light was an intermittent problem on startup and usually went away. I thought I would just nip this problem in the bud.

RAD4Runner

problem well-stated is a problem half-solved. What rubber thing? pics?


Not normal but expected of an old truck; pulleys/belt would fling oil at the alternator. Someday, when there's enough dirt deposits there, that junk could get conductive and cause shorts or mess up brush operation.

Intermittent meaning it could strike at the wrong place, wrong time. Fix it.
See charging system link on my sig. Has simple test points you could use.

Bruinpilot

Unfortunately I have put the alternator back together. I was planning on documenting this with pictures, but working on the alternator while tending a screaming 3 month old baby made this impossible this time.... There is just a rubber cap that goes over the brush holder assembly and the alternator shaft. I presume that its only purpose is to keep grease and dirt out of the brushes and the alternator shaft.

This is pretty much what seemed like happened. It looks like over time the lower brush got gummed up. It is a little strange though, I would have expected the upper one to get more gummy...


Thanks for the good reply. I am putting this alternator back in today or tomorrow. I will post back up how its working. Hopefully it works. If it does, this seems to be the way to go. Before junking an alternator. It is a really good idea to check these brushes. It seems pretty easy, but I can't really say that yet, I don't know if it works

Bruinpilot

Well got the alternator in this morning. Started right up and I've got 14.7 volts at the battery! So far so good. It was an intermittent problem, so I can't call it good for a few days, but I think that was it. I've got to say before buying a new alternator, try the brushes. It is easy, just be careful of the rubber cap over the brush holder, I tore mine, but it still seems to work anyway!

RAD4Runner

Cool to know you god it working.

Congrats!
3-month old and 24-YO babies both crying for attention