What is this?
 

Looks like a filter for the vacuum lines to me... is this correct? It seems pretty dirty - any ideas on why it is so clogged up? Also - I can't seem to find this part at the fastlane. It is marked with the Mercedes star, then 0000780656. The opposite side is marked 45 00158 901. Anyone know if there is a Bosch/Mann/Mahl equivalent I could order from my local parts store? Thanks!

-John

Standard after market filter
 

Hello John
Go to your local auto parts store, it is a standard after market filter.
Pull the filter and take it in with you.
I get the same filter; as a VW fuel filter from local generic auto part stores (Fuel filter Purolator# F21124).
Total cost; under $3.00 USD.

It is used as a vacuum system filter, just read a post on it yesterday, can not recall the issue that damaged the filter.

Hi John.

Do you have any problems shutting the car
off?

If yes then this might be a clue as to why it
is so dirty.

The only reason that someone would put a
filter in the vacuum system is to filter out
oil that is present.

Do a search on the shut off valve and
the vac pump.
Plenty of info on why and where the oil is
entering the vac system.

Louis.

the shut off valve, that was the topic.
 

Hello John
The filter is an OEM installed part on my 1985 300SD.
mb123mercedes is right; I recall the topic was the shut off valve.

It's not really there as a filter. It's there to alert you tp the presence of oil in the vacuum system, like from a leaking vacuum pump.