PeachParts Mercedes-Benz Forum - Won't turn off thread

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Won't turn off thread

84 300D. I'm after confirmation and or suggestions for bad shut off valve.

Oil at the 2 lines under ignition at the column - bad diaphragm?
All vacuum lines are connected
No warning what so ever with this issue
Vacuum pump is fine
Car runs and drives with key out of ignition and very well
1.5 year old tumbler and tumbler housing
Stops just fine with engine stop lever
Can I blow the oil out of the brown lines and improve vacuum, and rig-fix it?
Submit to shut of valve?
Test valve where brown lines plug in at column?
Anything I am missing?

If you are getting Oil in the Brown Vacuum Lines the only place it can come from is the Vacuum Valve on the Fuel Injection Pump.

Other then the Vacuum Valve on the Steering Colum I have not read of the guts of the Steering Colum or the Lock Tumbler having anything to do with an Oil leak at the Vacuum Valve on the Steering Colum.

If you have info on that post it so I can put it in my Notes.

I always thought oil in the vacuum lines was an indicator of a vacuum pump going bad.. I could be wrong though .

You might have an issue with your vacuum shutoff on the back of the injection pump. If you've got a MityVac handy, pull vacuum on the shutoff, if it doesn't hold then that's your problem. If it does hold then you've got a problem upstream somewhere. Try this the car running, if you pull vacuum and it shuts off you've got a vacuum supply issue for sure.

However, Its my experience that the vacuum shutoff slowly dies. The one on my 300SD took longer and longer to shutoff the engine until I replaced it.

Quote:

Originally Posted by JamesDean (Post 2908264)

I don't know about that. In order to create Vacuum the flow of what ever Air the Vacuum Pump Moves should be going back towards the Vacuum Pump.
In order to push Oil out of the Vacuum Pump it would have to create pressure instead of Vacuum. If it is creating Pressure and not Vacuum that should quickly show up when you brake.

And this time it was the rubber connectors/fitting for the brown and brown/blue vacuum lines at the vacuum switch on the ignition. Over the last 2 years a slight amount of oil had come up from brown/blue and expanded the rubber fittings.

No warning on this turn-off failure. Very easy fix.