Fixing Bosch WFK-2401 washing machine - replacing motor brushes?
I just fixed my Bosch wkf-2401 washer - 7 years old in 6/07. It didn't spin. It turned out to need only new brushes for the main motor, which were $36 + shipping from RepairClinic.com - and even cheaper from Bosch itself, I later learned.
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, both 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. (OK, you have to factor in another 5 minutes for removing the machine's back.)
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.
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
