Hole In Alternator Brush, Do I Fix It?

[D.I.Y. Mik]

I noticed my car charges badly, and worse when it is warmed up.

So i pulled the alternator out for a look, and found a hole in one of the brushes. Normally i wouldnt care but its right where it contacts.

Anyone know if this is the problem?

Should i grind it back? Or get a new one?

I need to get it charging properly again.

Ideas anyone?

[t_revz]

I highly doubt this is your fault but need to see the commutator (what the brushes run on) to see if it's arcing or getting a good connection. I would file it down a touch if your concerned as its longer than the other anyway but I doubt I'd file it myself.

I've got part no for brushes from ashdowns I can grab later for you or you can order generic ones on eBay if you get measurements. I had trouble first time I wanted them

What do you mean it doesn't charge well? Low voltage or low current output? Or light flashes?

Edit- if you haven't assembled an alternator like this before you push the brushes in all the way and insert something small like a 1mm drill bit through the hole in the back to hold them in place while the 2 halves are put back together. Just be gentle so the brushes don't break into pieces

Edited September 15, 2012 by t_revz

[D.I.Y. Mik]

Thanks for tracking part number, its a weird setup with the brushes sort of sealed in a box, dunno if i can dissasemble without breaking it.

old plastic makes it brittle too.

doesent charge well indicated by bloke who sold battery to me.

Have put a temporary volt meter from cig lighter and it shows 13.9 when cold, then gradually drops to 13.

Switching all my gadgets on or off makes only about 0.2v-0.3v difference.

The light doesent come on, but the manual says 13.9v-14.9, although thats a GTR manual.

Shows 2.5 ohms across the commutators, ok right?

Anyway ill clean everything, put it back and see how it goes, might spray the outside coil with clear just in case its shorting.

I wont file it as it may take ages to become flush again.

Drill bit, yes, thankyou, good idea.

Edited September 15, 2012 by D.I.Y. Mik

[t_revz]

Yes the regulator/ brush box can be Disassembled just try not to break it if you do.

13.8-14.4 is better but a bit each way is ok. If your not having start dramas I wouldn't be too concerned in case it's the location of your gauge making the voltage seem lower.

Brx40710 is for a 10 pack of brushes but wouldn't recommend doing them if you haven't before. Bit fiddly and have to solder quickly so heat from iron doesn't heat regulator components too much.

Slap it back together or take it to an auto sparky to do brushes and new bearings

Edit- cant really check commutator with a multimeter correctly. Really need to check current draw but it sounds ok

Edited September 15, 2012 by t_revz