Packard Forum Index » Post-War (1946-54)

How do I check the brushes on my generator? Does the generator have to be removed?

I have a 1949 22nd series Deluxe Eight.

Thanks for all advice. This is something I should already know how to do.

You don't have to remove the generator, just remove the brush cover (strap band) to inspect. Check for length (compare to ones always available on ebay for example) but if they are less than 1/4 inch or so, time for new ones. Also check that the springs that press the brushes against the armature have tension. Even if everything looks OK, probably wouldn't hurt to clean the armature a bit, and don't forget the oilers.

Thanks, Dave. I didn't know the band was the brush cover.

I'm on my way outside now! I hope that's why it's not charging.

My rule is if the top of the brush is below the top of the holder it is time to shop for new brushes.

While you are looking check the brush is not stuck by lifting it up and down. A stuck brush can cause a gen to stop charging.

The brushes are short - less than one half inch, anyway. They are marked as "Autolite 6-I" (perhaps 6-7... hard to read).

I see some brushes for $3 on Ebay right now, but they are a 3-brush set. Can I just toss the third brush out? The two brush pair looks identical to mine.

The commutator is nearly black.

What's the right way to clean up the commutator? Real fine sandpaper, held against the commutator while turning the pulley end?

Thanks to all for the help.

Last time I checked NAPA still had the correct brushes for your generator - try them first before you try to adapt some incorrect brushes.

Yes, by all means clean the commutator but NOT with sandpaper, the grit can get into the copper, the carbon brushes, even the bearing/bushings. At this point you probably don't know what is on the commutator so I'd first try a bit of solvent like gasoline or rubbing alcohol on a lint-free rag. Avoid stronger solvents, you can damage the insulation. If that does the trick, the residue was mostly oil and carbon dust and no need to go any further. If it is still dirty (not bright copper), then emery or crocus cloth, very fine grit, no more than is necessary. As you look at the commutator, you should see that the insulation between the segments is below the surface of the copper. If not, you probably should undercut the mica yourself or have a generator shop do it for you.

Quick, very related question:

Back in the day we used to use carbon tetrochloride to clean oil residue from the commutator and brushes. I know carbon tet is no longer sold, but is there a good alternative on the market?

You can clean with electric contact cleaner spray. To me brake clean spray looks, smells and acts the same but comes in a bigger can and is cheaper.

If there is an old time auto electric shop in your area they should be able to get the brushes. They may have them in stock. Sometimes you can take in your old brushes and match them up if they are not too busy.

If the generator was mine I would disassemble and clean it with a mild solvent like mineral spirits. Then take the armature and commutator end housing to an auto electric shop and have them resurface and undercut the commutator and install a new bushing in the end housing. While there, I'd buy a set of new brushes and a drive-end bearing. Then take all the parts home and reassemble it. If this kind of work is beyond your experience level, then have the shop do all the work. A good working generator is important to driving these old Packards and the cost for overhauling one is relatively inexpensive, especially for the peace of mind it brings. Here are two photos of the generator from my '47 Custom Clipper. Good luck.


(o{I}o)

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I kept a can of CRC's Lectra-Motive cleaner (#05018) on hand for the shop in the GM store where I used to work...

http://www.crcindustries.com/auto/content/prod_detail.aspx?PN=05018&S=N

...for some of our customers with good old GM cars for which brushes, bushings, bearings, etc. were still available (if only in the aftermarket).

IIRC, this product uses essentially the same ingredients as their original Brakleen product, (#05089, NOT the new, non-chlorinated stuff), but in different ratios.