Vacuum Issues - PeachParts Mercedes-Benz Forum

Lonesome 300CD · #1 05-04-2007, 03:53 PM

Hey Everyone,
First of all thanks very much to all who have aided in solving previous problems. The advice has been great. Anyway, I've got an 84 300 CD Turbo. I've just replaced the head and have it all put back together. While taking it all apart, many of the vacuum lines became unattached, and I don't know how it goes back together. It's mostly the cluster of lines as you get near the firewall that I'm having problems with. Is the system directional? If I have everything plugged in, does it matter what it's plugged into as long as it's part the of the vacuum system. My concerns are the cluster of lines nearing the firewall. Can anyone direct me to a diagram of the system, or give a pretty good detailed description of system so that I can reassemble it?

Thanks verrry much for any help

apsaulters · #2 05-04-2007, 04:13 PM

You might find these posts useful.

Vacuum Diagrams
W123 Vacuum InterLock Diagram

Lonesome 300CD · #3 05-04-2007, 04:38 PM

Just what I'm after....Thanks!!!

Paul Ellis · #4 10-12-2007, 08:21 PM

Hi, I have a 1981 300d with a vacuum problem. I pulled the green/yellow stripped hose out of the drivers side near the steering wheel and I don't know what it hooks up too in the cockpit. Had a massive vacuum leak and have been trying to find out the problem when I noticed the line was disconnected. I have read all the threads and did learn about the orifices. Would like any help. I also have a 1984 300sd that has a bad vibration at idle.... read where the rack bolt has something to do with it? Thanks again (helped me out on the rear axel bracket bolt to the frame....use a 6 ft bar and break the rubber-steel collar to bolt loose). Paul Ellis

#5 10-12-2007, 08:32 PM

It looks like that line goes to the HVAC distributor under the dash, see attached diagram:

http://home.comcast.net/~phantoms/vacuum/heating_ac.jpg

hitwtom · #6 10-12-2007, 08:36 PM

Quote:

Originally Posted by Paul Ellis

Hi, I have a 1981 300d with a vacuum problem. I pulled the green/yellow stripped hose out of the drivers side near the steering wheel and I don't know what it hooks up too in the cockpit. Had a massive vacuum leak and have been trying to find out the problem when I noticed the line was disconnected. I have read all the threads and did learn about the orifices. Would like any help. I also have a 1984 300sd that has a bad vibration at idle.... read where the rack bolt has something to do with it? Thanks again (helped me out on the rear axel bracket bolt to the frame....use a 6 ft bar and break the rubber-steel collar to bolt loose). Paul Ellis

Bad vibration at idle could be an engine mount, had that problem on my old 300D.