'87 300D Vacuum line replacement

[Ravenswift]

Hi guys. I recently decided to get to work on my '87 300D (OM603) so i could use it as my DD again.



One of the things I need to do is replace %90 of the vacuum lines, as they are all dry rotted, torn, chewn through by mice, etc. I've found the diagram for the vacuum lines under the hood, however it appears that somewhere along its 450kmi life, some of the vacuum lines going through the firewall have been changed or removed (at least that's my assumption...maybe I'm just as dumb as I look and can't figure it out when I thought I could.) The color coding on the diagram I have doesn't seem to line up with whats there. I have a white, green, small black (big black is deleted from egr delete), red, and blue, however it appears the diagram calls for sw(schwarz-black), br/bl (braun/blau-brown/blue), gr(grau-grey), and br (braun-brown).



What am I missing here? I suppose it was a total n00b mistake to pull all of the vacuum lines out at once instead of replacing them one at a time

[Diesel911]

As you found out the under the hood vacuum sticker only shows the under the hood stuff.
Someone will need to post an online source of the Mercedes service manual for your year and mode so you have the full vacuum diagrams.

I don;t know if yours has this but some models have an electric vacuum pump in the trunk to deal with the locking system and so on. I don't know if yours has that.

[sixto]

Double check that the diagram is for your car. IIRC there aren’t that many vacuum lines crossing the bulkhead in an ‘87 300D. Brown is vacuum for the key switch, brown with [red?] stripe is for the engine shutoff valve, yellow[?] for ACC and green[?] splits from yellow just before or after the bulkhead for rear headrests. You know about the black vent line. Someone might have added lines for a boost gauge or other telemetry.

There used to be a vacuum diagram thread among the stickies.

Sixto
98 E320s sedan and wagon
02 C320 wagon

[Ravenswift]

I haven't look in the trunk much to see about an electric vacuum pump but right now I am mainly focused on the engine compartment.



I took a look again and these are the lines I have coming through the firewall. Could someone help me clarify because I don't want to hook something up wrong?



- red w/ blue stripe = shut off valve?

- green w/ yellow stripe = straight to vacuum pump?

- solid white = ??

- solid brown = brake booster non return valve?

- small black w/ grey stripe = ventilation to cab for bottom part of injector pump?
- large solid black = deleted (EGR delete)



I get the feeling none of those are right..


Also on another note, I accidentally pulled out the line that goes to the transmission (i was moving it around too much). Does anyone know where and what i should be looking for to hook it back up? because I cant find anything...




This is the diagram I started with but the color coding just doesn't match up. I do have an om603 so this should be the correct diagram.

[Ravenswift]

I think I figured it out!

-red/blue = fuel shutoff valve
-green/yellow & white = straight to vac pump (green/yellow is climate control, white is rear headrests
-brown = brake booster non-return valve
-small black = vac control valve vent
-large black = EGR transducers vent (for those of you wondering, this large line goes across back of engine compartment from the fuse box area, across to battery area, down inside the fender, and into a vacuum canister)

Fingers crossed that this is correct! thanks for the help guys!!!