Author Topic: What parts are these (related to the climate control vacuum system)?  (Read 236 times)

avantbenz

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I'm trying to get my air conditioner working in time for summer and obviously getting a late start. This involves tearing apart my dash and looking for things that are old and probably need replacing.

I found a yellow vacuum modulator type thing that doesn't seem to hold vacuum (although I'm not sure it's supposed to so there is that). Can someone please identify this and point me to a place I can buy it?

And this other black mod type thing also isn't holding vacuum. Does it need replacement? Any tips on best places to buy it? I found a few but always open to suggestions.

Pics here: https://imgur.com/a/sw7eaf7

Daily Driving 'Patience' ~ 1980 300SD

avantbenz

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The black vacuum modulator thing is labeled: 123 800 0578 but I'm actually having a hard time finding it for sale. Lots of similar looking parts are popping up but none with the exact same part number. Please help!
Daily Driving 'Patience' ~ 1980 300SD

Alec300SD

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It is a check valve and should hold vacuum when suction is applied to  the side opposite the black end (blue or white).
If it failed, just substitute the cross referenced MB part number 123-000-00-78 .
79 W116 300SD 'Stormcloud' new as of 10/22/2017
78 W116 300SD 'Desert Rose' new as of 01/26/2014
83 W126 300SD 'Rena 2.0' with engine from 82 W126 300SD Rena' (SOLD and crushed 11-20-2017)

avantbenz

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Thanks Alec300SD, I ordered the 123-000-00-78 via Amazon and it should arrive tomorrow.

I'm holding out hope someone knows which part the yellow valve is and where to find it. 
Daily Driving 'Patience' ~ 1980 300SD

Alec300SD

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Two yellow vacuum switches (item 20 and 23 on page 9 of the pdf) MB part number 000-800-05-73.
http://handbook.w116.org/Climate/83-600.pdf

Available at the dealer, or online.
https://www.mboemparts.com/oem-parts/mercedes-benz-switch-ventilation-0008000573

Not sure how to test them though.
79 W116 300SD 'Stormcloud' new as of 10/22/2017
78 W116 300SD 'Desert Rose' new as of 01/26/2014
83 W126 300SD 'Rena 2.0' with engine from 82 W126 300SD Rena' (SOLD and crushed 11-20-2017)

avantbenz

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Wow...that PDF is terrifying and potentially invaluable. So many things that can go wrong it makes me cross-eyed. Thank you for the resource and the info, Alec300SD.

Can anyone chime in on thoughts of how to test the vacuum switch? It's about $25 and I'd rather not buy it unless I knew for sure it didn't work.
Daily Driving 'Patience' ~ 1980 300SD