Hi, I am a happy new owner of an "old" '91 300SEL.
The car is fine, but the vacuum system (central locking etc.) needs quite some care.
I know the previous owner replaced the vacuum pump unit (under rear seat) recently, but it has already broken again.
It appears that the pump itself was filled with some oily liquid, and that the rotor of the pump mechanism was physically broken (splintered), probably because of overload due to the liquid in the chamber. I looks like the liquid comes from the transparent vacuum line, which is the manifold vacuum assist line from the vaccum distribution block and thereby from the vacuum system controlling the heating and A/C (which does not operate well either).
The car has facelift to W220, and the vaccum control of the headlights is therefor disconnected. I suspect the leakage may come from there (as one possibility), and I have ordered a Mityvac to troubleshoot the complete vacuum system further.
Meanwhile, is there anyone who knows, where the oily substance may come from?
And not least, does anyone know where to obtain a replacement pump motor/mechanism (possibly with a worn down motor) or the pump mechanism itself (instead of the bloody expensive complete unit)?
Thanks in advance.
/Jens (Denmark)
PS: I am new to this group. Please excuse me, if the problem has been addressed earlier (I couldn't find it in Google)