My Euro 1985 300td has a bad one of these, looks and is almost identical to the ones found on the 87tdt and d, anyway if youve got one pls pm me.
thanks

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Ages ago I posted how to take the VCV apart to replace the rubber pad so it holds vacuum again. The hardest part is removing the orange cover with very stiff tabs.

Let me know if you can't find the thread or need a recap.

Sixto
87 300D

How did you cut the new rubber diaphram? Was it perectly round? I am getting the feeling that my VCV is not holding vacuum and needs to be replaced/repaired.

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95 E300 Diesel 200K

The diaphragm isn't a seal. It's just an oil barrier. The rubber pad is about 5mm in diameter though I cut the replacement more like an octagon. The shape isn't really critical since it's function is more of a snubber for a small tube at the end of the vacuum supply line.

Here's the VCV off the IP. I gently drilled down the rivet flares to remove the plastic case from the metal cover. This isn't absolutely necessary if you can remove the orange cover. I couldn't remove the orange cover (mine's black) with the metal cover in place -



Here is is the metal cover off the plastic case. The diaphragm doesn't seal anything. Not with that big hole for the vent fitting anyway -



This is the plastic case with the valve mechanism removed. Nothing to do with this other than clean it -



This is the valvetrain. I think things are in the right order The metal tube at the center of the orange/black cover presses against the rubber pad a couple of pieces down to hold vacuum. As you apply throttle, the pad drops from the tube to allow a leak. In this picture the rubber pad is worn down to an o-ring. It should be a solid disk -



Here is a picture of calipers showing the diameter of the rubber pad. As I said I cut a piece of rubber closer to an octagon and it works -



Here's a picture of calipers showing the thickness of the rubber pad. The bicycle tire inner tube I used for the replacement pad was close to twice as thick as the original pad. Doesn't seem to be a problem -



I found that common household wallplate screws have the right thread to self tap into the remaining rivet sleeves. It looks ghetto but you ghett what you pay for.

Sixto
87 300D

Great pics! Here is a pic of mine. Doesn't have an orange cap. It has a white one. A couple of questions:
If you can get the plastic cap off, do you need to open the body?
Does the valve train explode apart when you pop the cap off?
The wall plate (from an electric outlet?)screws self tap?

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95 E300 Diesel 200K

No. The metal cover can remain attached to the plastic case so you don't have to worry about the rivets. Good luck with the shield part of the metal cover.

I don't think there's much spring force.

Into the rivet sleeves, yes.

Sixto
87 300D

it looks like the sleeve sits snug to the cap and wont allow it to expand to be popped off.

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95 E300 Diesel 200K

Looks like its functionally identical to the old style used on the OM616/7. It may have internal parts that cross over.

here it is from another angle

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95 E300 Diesel 200K

The bolt holes are slotted and looks like the like the VCV can be adjusted. What is this adjustment for?

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95 E300 Diesel 200K

The VCV setting is adjustable. IIRC, you hold the throttle wide open then turn the VCV CW as viewed from the driver side fender until you feel resistance from the internal spring. The manual has diagrams and more words but that's basically it.

Sixto
87 300D