I need to know which way the bosch brushes should be inserted in to their holders. When fitted the motor makes a loud clicking and trips mains earth switch at around 1000 rpm.

Bosch Maxxx WFL 2260

Thanks

mark, July 2005

I am not a washing machine engineer but a practical DIYer so apologies for any incorrect procedures. One thing I have noticed though is there isn't much mention of the commutator causing the problem but the brushes.

However as soon as the motor sounds "different or rough" I turn the machine upside down to remove it for a closer look. Do the wire and water thing first and use a towel or something to protect the machine when turning over.

At about five years I used some emery paper to clean the commutator through the end housing (hold emery paper and turn shaft). I didn't take the brushes out but did use an airline to blow the dust out. Sounded good when replaced.

At about nine years repeated above but the motor didn't sound so sweat on refitting. Again I didn't remove the brushes.

At eleven years it was a bit more serious. The commutator wasn't in such good condition and needed more attention. Using one of those star type allen keys or even an allen key I removed the four bolts to dismantle the motor. Observe position of thrust washer and a flat one. With commutator removed and an extra pair of hands to hold it still I used a strip of emery paper about 200mm x 10mm and cleaned it until the grooves and marks where the brushes make contact were gone (nearly). I gather this could be done on a lathe.

To make life easier for reassembly I removed the brushes (as already described) . They were worn to about 30% and I didn't think the springs were exerting sufficient pressure to make a firm contact with the commutator. If it wasn't the weekend I would have bought some new brushes but in the end I removed springs and stretched them. This worked a treat and the machine is now purring away happily.

I am wondering if the rest of the machine at eleven years old will keep going long enough to make it worth buying a new set of brushes to keep as spare.

Mike, January 2012

I just did the same fix-it job for my Bosch wkf-2401 washer - 7 years old in 6/07. Brushes are $36 + shipping from RepairClinic.com - and even cheaper from Bosch itself, I later learned.

First, I read the above description carefully, following all safety precautions. I also took lots of photos of the machine before surgery, just in case. And I made a point of sketching a few important items.

Removing the motor was the tricky part; I couldn't figure it out, at first. There were two bolts to remove, obviously, but I couldn't see what to do next. Eventually, I realized that the belt needs to be removed from the motor's axle-thingie - the grooved circular pulley, I mean. Then, the motor comes off like butter. It's actually a clever design.

Two different repair companies - authorized by Bosch - told us we needed a whole new motor for $350 parts and labor. When we suggested that maybe it only needed new brushes, they said, Oh no, that would cost even more than a full replacement, so much labor would be involved. In fact, once the motor is removed (10 minutes, max, once you know what you're doing, replacing the brushes is about 5 minutes' work. The main thing to watch out for is that the end of each brush is cut at an angle and these brushes touch the motor's commutator (the set of copper contacts that the brushes actually touch inside) tangentially, not radially. So, you just have to make sure you insert the brushes the right way - common sense will show you; just imagine that the flat surface of the brush's angled end has to make full contact with the edge of the circular commutator down inside. Once you've got one brush done, the other one is inserted with its end situated in the opposite way. Like so, sort of: ----\ O \---- !!!!

Also, before removing the more, you have to clip the cable ties that hold the incoming wires to it; otherwise, you can't actually remove the motor from the machine and you're likely to put dangerous stress on those wires and have a real mess on your hands. Of course, when clipping those ties, you have to make very very sure not to clip any of the wires they are holding!!

One thing I overlooked when first reassembling the machine was putting back the sheet of plastic that covers the motor and protects it from water. This is an important item, I have read. I am not entirely clear about how tight the belt should be; time will tell, I suppose, if my estimate was right.

Though I have some intuitive understanding of motors and mechanics, I have never done anything like this before. So, I am pleased with myself for having overcome the manufacturer's obfuscation and its agents' greediness.

John Verity, in NJ, September 2007

Hi
This is the way I do it. It saves scrabbling about on the floor!
Switch off power, disconnect hoses, open pump housing to completely empty machine of water.
Turn the machine upside down onto a soft surface - eg a blanket on the floor, and carefully cut the cable tie holding the motor cable and splashguard to the motor body; disconnect the motor connector and earth spade to facilitate easy access to the more visible brush block. The brush spades disconnect easily, then the brushes are extracted by sliding each spade terminal inwards toward the motor spindle until the connector end is released from the block, then pull the other way to release the inward end - withdraw the spring/brush assemblies gently from the carriers. The brushes are clearly on either side of the motor spindle but see how they do not fit on a diameter of the motor axle but are inserted tangentially - the curve on the brush is polarised to take this into account - you want to have the wider carbon contact surface of the two fitting options possible. Reassembly is simple but make sure you do not reconnect the mains supply if any water has been spilled into the top of the machine... leave it for a day or so to dry out (I've never had such a problem but I have to say this!!).
You can test the motor using the spin cycle before re-installing the machine properly.
I gather there are two types of brush fitted - I've had no experience of the other type but it should be a service item.

Hope this helps. Regards

John, July 2005