Regreasing Original 7424, NOT XP

Hey all,

Anyone know how to do this? The original 7424, not the XP.

I watched a video on youtube showing the breakdown and regreasing of the XP, and it is very similar.

Seems as if the only difference are the way the brushes are in place (mine are around a plastic housing held in by a torx screw.

I would assume, if I wanted to do it right, I would have to remove the brushes and pull out the armature.

Anyone have experience? I am turning this PC into a dedicated 3 inch with the backing plate sold here on autogeek.

Another question...how to tell if the brushes need replacing.

Any help appreciated.

Eric

Not sure of your personal electronic-mechanical expertise, but sometimes less is better.

In other words, maybe not rip the machine down to every last screw, nut and electrical connection. The old adage comes to mind, if it isn't broke, don't fix it.

A can of canned air, or lightly blow out with compressed air, a soft small painter's brush to just get out the cobwebs and get the armature area as clean as possible.

Something like popsicle sticks could help dig out old greases and replace with fresh. Super Lube Synthetic Grease will work well.

I reckon you could check the brushes one at a time, and if there's decent meat on them you should be OK. Put them back in the exact same way-orientation as you removed them. Blow the receptacles out with a little canned air and replace.

One could always order a set and then replace them at some future point if needed.

If you are only going to re-grease it you just take the backing plate and the cover of the gear house and the plate into the gears. Take out the grease as good as possible and fill it up again with the amount of grease that was in it. Use a lithium high temp grease of great quality. Don't remember which brand Apex Detailing Channel on Youtube do use when he does switch it. Something that starts with Wolf.... IIRC. Use a cotton swab to get the gears cover and when you start it up do it on the 1 speed setting and let on for a while so the grease spreads out.

If the polisher works as it should I would not change the brushes. But if you take of the houseing if you don't have 2 bigger plastic screw covers on each side for easier getting to the brushes. And if you are able to see the hight of the carbon brushes and compare them to a new ones. You see how worn they are. If they are close to the electric cable is attached or maybe under 1/5 of the new brush I would switch to new ones. But no need to be takeing the electric motor parts out if you change the grease and or the brushes. The brushes can have some different locks but useally not so hard to figure it out.

Hope it helps you some.

/ Tony

Thanks for your reply...the gear mechanism is a separate piece, so it seems somewhat different than the XP teardown I saw; didn't have to remove the brushes, or the armature.

Amazing, the armature and the brushes are still in great shape...this thing has got to be gong on for almost 20 years (I think I bought it when I joined the forum ;)).

The front bearing near the backing plate is sealed, but the two around the armature aren't, so I lubed them, and can't quite get rid of the old grease totally (unless I wanted to soak the entire head. I'll just get rid of as much as possible, and repack it with the red stuff.

The brushes are housed in a plastic shroud. Word of caution: when removing, the spring mechanism may fly off the back of the brushes (wasn't too difficult to get it back into place).

Also, the bushings are using, on this model, a 9 mm torx, not a 10mm like mentioned in the video, and in order to get at one of them, I had to remove the switch relay (just slides out).

Once again, thanks for the input, and the warning (my dad used to get quite angry at me for pulling things apart and putting them back together, but all in the name of science ).

Eric

Nice that you did change and lubed it up again. They just don't always build it in that quality anymore. There are the knowned brands that does it and a few brands that want in to the market and build with high quality. And polishers is not alone as it's many machines with electric motor that is of very poor build quality. Washer machine is one of them that the manufactures hope will last around at most 10 years and then fails. The older washers seems to be holding up to eternity LOL. But new times or this has been going on for a longer time with the washers at least. But powertools is showing more signs of this too. And it's not only the electric motor on the machines but bushings and gears and bearings that also has a lower quality than before more and more. Then setting the prices on spare parts at a high level makes to buy a new machine instead. It's a conspiracy going on LOL.

Agree on quality of workmanship...this thing is a tank.

E

I switched the counterweight from 6" to a 5" for using my 3.5" pads on my PC. There isn't a big difference but there is a slightly better feel with smaller pads.

Quote:

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Originally Posted by Paul A.

I switched the counterweight from 6" to a 5" for using my 3.5" pads on my PC. There isn't a big difference but there is a slightly better feel with smaller pads.

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Hmm, that makes me wonder if the 5" Counterweight Size might be a better choice with possibly less vibration-better balance, for running 5" Backing Plate and 5.5" Pads versus the stock 6" Counterweight that comes with the machine?

Have you tried this I assume smaller Counterweight with the 5" Backing Plate, and smaller 5.5" Pads and noticed any difference in operation?

Yes, again, not a huge difference but noticeable enough to feel. I have a PC 7336 so it's old! I don't use any pads bigger than 5.5" on it.

I do find it stalls on more radically curved panels a little easier than when I had the 6" weight on but I don't use my PC for serious correcting work...mostly small area refinement and LSP applications.

Quote:

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Originally Posted by MarkD51

Hmm, that makes me wonder if the 5" Counterweight Size might be a better choice with possibly less vibration-better balance, for running 5" Backing Plate and 5.5" Pads versus the stock 6" Counterweight that comes with the machine?

Have you tried this I assume smaller Counterweight with the 5" Backing Plate, and smaller 5.5" Pads and noticed any difference in operation?

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Dusting off the cobwebs of some knowledge obtained from the PC was the only DA in town - The counterweight size on the PC is really for sanding, not for polishing. The size/weight of the foam pads negates the 6" to 5" counterweight change.