I attached two photos, one to orient you on where I found these and then a close up of the parts.

There are 2 hoses, apparently vacuum lines.

The 3rd part is half of an electrical component that has sort of like 2 holes for something to plug in there (positive and negative). I'm thinking these 2 vac hoses would go into whatever electrical part that is missing.

My mechanic thinks they plug into a part on the engine that controls the turbo so it doesn't overspin out of control and blow up.

His online diagram service says it is an "engine overload protection valve". He says that it plugs into the aneroid compensator. Does anyone know what this missing piece is or where I can get one, or a part number? Or can someone post a photo of theirs so I can see what's supposed to be there. I think there's a part that gets attached with 3 screws up closer in the direction of (but not on) the firewall that these hoses get attached into.

Thanks,

jeff 1991 300d

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If someone posts a photo at least then I'll get a visual of what's supposed to be there. I think there's a part that gets attached with 3 screws up closer in the direction of (but not on) the firewall.

I could probably take a picture of this on the weekend on my car, if no one else has yet. I have a 90 300d.

I took 2 pictures ( different angles ) of my 6 cylinders 300D. It should be the same as your 5 cylinders but not sure. I think you may be missing a vacuum switching valve. You can check the vacuum diagram.

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__________________
Not MBZ nor A/C trained professional but a die-hard DIY and green engineer. Use the info at your own peril. Picked up 2 Infractions because of disagreements. NOW reversed.

W124 Keyless remote, PM for details. http://www.peachparts.com/shopforum/mercedes-used-parts-sale-wanted/334620-fs-w124-chasis-keyless-remote-%2450-shipped.html

1 X 2006 CDI
1 x 87 300SDL
1 x 87 300D
1 x 87 300TDT wagon
1 x 83 300D
1 x 84 190D ( 5 sp ) - All R134 converted + keyless entry.

Ah-kay, thanks for posting the photos. Jdulle, go ahead and post some photos since yours is more like mine and we'll compare.

As it turns out, those "2 hoses" that I thought a piece plugged into in the middle, was actually "1 hose" the curves, and it broke. So I had to get a new piece of hose and all is well.