View Full Version : Motor brush question

10-15-2008, 09:12 AM
Hey All,

Recently my angle grinder (AEG model ws 601) croaked while running....I thought it was beyond my help as I'm not too knowledgable about that end of things.

Anyway, I took it apart a bit and saw one of the brushes was being kept from making contact due to a spring loaded "point" that had been allowed to come through the contact end of the brush.

I removed the point and spring and re-assembled it and now it works fine. My question is: should I not have done this?....seems like it might have a lot more wear left so I didn't know if this was just a device put in place by the manufacturer to let ya know the brushes need replacing.

Sorry to ramble, any help would be appreciated...I was having trouble finding a source online for replacement brushes so that's why I didn't just replace them also.



10-15-2008, 10:11 AM
It probably needs new brushes and you should get some now.

10-15-2008, 01:33 PM
the spring loaded point is to raise the brush off the armature when it needs replacing so it will automatically shut off the tool, thereby saving unnnecessary arcing on the communtator. (did i spell that right)

aeg was bought out by chicago pneumatic, the bought out again by milwaukee. parts may be difficult to find. i may have brushes in my collection if i had a tool model number.

10-15-2008, 11:04 PM
Thanks for the replies guys....David, yeah that's what I figured...it jumped it up out of contact. I'm sure the other one is due to follow suit soon.

The company buy-outs are helpful to know in trying to track stuff down...thanks.

It's the 4.5" grinder, and the case shows an ID# 312496 and a mach. # 374847.

I'd be more than happy to compensate you for your expense and trouble if you found a set...that'd be super.

Thanks again,


10-16-2008, 03:10 AM
If you find it hard to locate those brushes, keep in mind that a lot of tools will use a brush of similar compound and size. I would take one out, measure it, make note of the position of the wire, then go ask a tool repair place if they have any brushes on hand that you could measure up. Chances are good that you can get one the same size, or if larger they are easily sanded down to size. It's dirty work, but doesn't take long, and if it brings a good tool back to life, the time spent might be worth it.

Whenever possible, I like to contour the brush to fit the comm as best as possible before it gets run. The best way to do that is with some sandpaper wrapped around the comm, and the brush in contact. Pull a strip of sandpaper back and forth around the comm to fit the brush. Sometimes it's easy, sometimes not. The sandpaper should be 'worn out' on something before it's used for this. That breaks off the loose abrasives and gives you a better chance at not embedding a piece of abrasive in the brush, or the copper.