I removed the panel below the steering column today to check my cruise amp. When I pulled it out I noticed oil drops on the foam insulation where it connects to the vent. There were only a few drops but it was definitely there. Any guesses as to where it came from?

Well since the SD uses an electrical oil pressure gauge, It must be coming from the shut-off vacuum system. As the diaphram (at the rear of injection pump)leaks, oil is sucked through the vacuum system, which goes to the ignition switch. It eventually is pulled back into the motor through the vacuum pump.

Unfortuanately the rubber connections don't like the oil and usually swell up till they leak oil and/or vacuum. This occurs at the back of the ignition switch.

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Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician

I just replaced the vacuum shut off switch, which was bad, so maybe I fixed the leak. Should I try and blow out the vacuum lines?

Yes, you have already solved the problem. You should probably replace the rubber hose connections at the shut off switch (in dash). If the oil has gotten out of the lines the rubber is probably mushy and likely to eventually leak vacuum.

The vacuum will eventually suck all the remaining oil. It won't hurt anything but the rubber links.

__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician