Air Pump Pulley Bearing and Filter Replacement

[luckymike]

I'm in the process of changing the pulley bearing on my '95 E420 air pump. Anyone done this lately and available to offer any tips?

I'm planning to grind away the small, displaced metal tabs at the back of the pulley, press the bearing out and replace it.

Also, I discovered that the box on the back of the pump contains a filter! I had no idea. I cannot find a part number for this filter. Anyone know it?

 

[gsxr]

I don't think the filter is available separately.

I thought there was a thread here already for the bearing, but I can't find it... here's my notes on the topic:

Smog pump bearing, MB # 001-981-42-27
INA # L32/52 2RS AH03


As of Nov-2014:

INA currently has no stock on this bearing , it has not been produced since 2006.
It will have to be quoted from INA Germany, I will let you know as soon as I hear back from INA.

Motion Industries 03009493 (appears to be NLA by 2017):
https://www.motionindustries.com/productDetail.jsp?sku=03009493


Aftermarket bearing ($20)
32BG05S18G-2DS A/C Compressor Ball Bearing 32x52x18+20
http://bearingsdirect.com/automotiv...s-a-c-compressor-ball-bearing-32x52x1820.html


...try replacing the bearing instead of buying a replacement pump. Read this thread, see post #4:
http://www.benzworld.org/forums/w124-e-ce-d-td-class/1421046-smog-pump.html

I couldn't find any detailed bearing replacement threads, this one had a decent photo and some more information:
http://www.peachparts.com/shopforum/tech-help/292005-air-pump-bearing-removal-92-400e.html

Another thread:
http://www.peachparts.com/shopforum/tech-help/168879-air-pump-bearing-removal.html

I just saw another good writeup with photos, here's the link (Photos gone 10/2016)
http://124forum.dk/w124/files/viewtopic.php?f=25&t=2005&start=0

 

[luckymike]

Thank you. I've seen some of those, too.

We'll see how it goes...

 

[roadster27]

If it's the same pump as the ones on the M104 engine cars it's not a difficult task. I'm sorry I can't remember where I ordered the bearing from, but it was one of those peachparts links that pointed me to the seller. Let us know how your project goes.

 

[Steve119]

My bearing also was making a slight noise on idle.
I took off the pulley, opened the bearing and sprayed 2 cans of brake cleaner in it. Fully regreased it after that and it's been running quiet and smooth for already over a year

 

[luckymike]

Closing the loop on this thread:

I could not find the proper bearing in the United States. My 1995 E420 requires a bearing with dimensions 30mm x 46mm x 18mm. It appears this bearing is proprietary, at least in the U.S.

I understand, per post #10 in this thread: http://www.500eboard.com/forums/showthread.php?t=11776&p=150628#post150628, that this size bearing is available in Poland. So European owners may have more luck.

I wound up finding and purchasing a used air pump at a dismantler. I bought it with the intention of swapping the pulley/bearing to my pump but it actually sounds smoother than mine so I'm just going to install the whole thing.