Can anybody describe the proper procedure for replacing the blower motor brushes for Siemens blower motors? I've found some descriptions but it looks like the Siemens ones are different...

Is it possible to get the plastic fan part off the metal shaft? It looks like that is necessary to gain access to the blower motor brushes...

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'81 300TD Wagon 355k (Miss Diesel)
'83 300SD 180k
'84 500SEL 190k (Parting it out)

Oops -- were you planning to use those Bosch brushes I sent you on a Siemens motor, Andreas? Won't work, they're different.

The Siemens motor does indeed have the brushes under the fan cage, opposite of the Bosch motor. You can use a hammer and drift to drive the motor shaft out of the fan hub. It comes off pretty easily with a few moderate taps.

The brushes are easily accessible once you get the fan off. They pivot against the commutator, with an expansion spring maintaining pressure.

Is the motor dead? The brushes on those Siemens motors look like they'd last forever.

Russ M.

I hadn't even pulled out the motor to check it until I got your brushes. Sounded like the Siemens was rare so I didn't think I'd have one ;-).

I had some problems with the blower a month ago but they turned out to be vacuum-related (vents weren't opening all the way) so it seems the blower is okay as it is. I thought I'd replace the brushes anyway as a preventative measure while I had the time (sounds like they're prone to wearing out at this age) but since you say mine will last practically forever I guess it isn't much of an issue .

I've opened my motor enough to see the brushes (Just can't get at them easily since they're on the wrong side) and they look absolutely identical in dimensions to the ones you sent me, so I don't know why they wouldn't work if I could get to the area. But since it doesn't seem necessary, and I've already tried more than a few much-harder-than-moderate taps to get that damn fan off, I'll just leave things as they are. I know enough people with 123's that I'm sure these brushes will come in handy sooner or later .

Since I have the fan completely apart, I might as well take the chance to clean it out. I've already scrubbed out layers of dust and goo that has collected in a couple areas... Can anyone tell me what would be best to lubricate the relevant parts of the shaft with? Grease? ATF? WD-40? ... ?

Thanks for your help, Maki!

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'81 300TD Wagon 355k (Miss Diesel)
'83 300SD 180k
'84 500SEL 190k (Parting it out)

My patron saint of Diesel, Dr. Booth, recommends automatic transmission fluid for the bearings. If you can't get the fan cage off, don't worry about it. There's nothing under there you need to be concerned with.

I took the cage off the Siemens motor from my coupe with a couple whacks on the drift from a 2-pound masonry hammer...it came off cleanly and I found massive brushes, like 3/8 inch by 1/2 inch swept area. That's about three times the swept area of the Bosch motors, I'd guess. They look REALLY German, if you know what I mean. How come MB didn't contract with Siemens for ALL the electric stuff...

While you're cleaning it up BTW, look out for the odd little metal balance clips on the vanes of the fan cage...

My wife and I were in SoCal four years ago to buy our 300cd. As Rust Belt denizens we were stunned by how many '80s Mercs were driving around. But man it was HOT, so if any left coaster can use those brushes to keep the breeze blowing, all's well.

Good luck, budd

Russ

Hmm, mine definitely aren't that big! I'll try getting that fan off one more time, just because it's hard to clean otherwise and I can tell there's still some dirt under it.

Yeah, there are old Mercedes of all kinds everywhere here. I've noticed at least two '87 300TD's in my town; I hear those are supposed to be rare. It gets pretty damn hot here, but to me it seems like it gets even hotter everywhere else! Last time I was in Minnesota in the summer I was about ready to die; is Wisconsin that much better? And I dread driving through Texas next month...

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'81 300TD Wagon 355k (Miss Diesel)
'83 300SD 180k
'84 500SEL 190k (Parting it out)

Well, I confess I'm on my third beer tonight, maybe I'm prone to exaggeration on the brushes at this point. I don't think I'm too far off, tho.

As for temperatures, the Great Lakes keep us pretty temperate. It might have hit 80 here today where I live; where I work in Milwaukee it was at least 5 degrees cooler. Of course, we also had a tornado to duck today! But it's been a weird summer. Most of the time the tornadoes prefer Missouri and Illinois.

My dad's hometown is in Michigan's upper peninsula. Man, if you want cool that's the place. Lake Superior is a natural refrigerator (second-deepest lake in the world after Lake Baikal, if I remember correctly). Maybe you'd enjoy it as a summer getaway sometime! We're dying for Isla Mujeres around February, I can tell you that. Everybody is searching for moderation...

Then again, I hear Santa Barabara is pretty close to paradise. You just have to have the green matter to pave the way.