I just bought a 1983 300cd and I have convinced myself, after much research on this site and the internet, that the vacuum lines on the car are not currently hooked up right. I am having shifting issues, etc. Some of them are probably not vacuum related but from everything I have read this is the place to start. I can't seem to find anywhere a vacuum diagram that matches the setup in the car. Some aspects of what I have found posted are correct but once the lines hit the vacuum control valve i'm guessing. Can anyone lead me to proper vacuum diagram routing for this model car? I have a 5 way splitter off of the check valve that is confusing me the most. I beleive I know where everything goes off of the seccond orifice, down to the dashpot to the vacuum control valve. to the transmission line. I just need some help.

One invaluable tool you will need is a MightyVac.

Mine came used from ebay at about 15% of new price.

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1985 300D 198K sold
1982 300D 202K
1989 300E 125K
1992 940T

"If you dont have time to do it safely, you dont have time to do it"

"The democracy will cease to exist when you take away from those who are willing to work and give to those who would not."

If you don`t get it ironed out, bring it to the GTG May 22.

http://www.peachparts.com/shopforum/showthread.php?t=275432

this site might be of some help

http://www.peterschmidtransmission.com/vacuum.htm

Charlie

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there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works

This one was helpful for me if you are troubleshooting the side that goes to the door locks:

http://ericandkat.com/mercedes/W123VacDoorLockDiag.JPG

Also if you look under the front carpets, driver and passenger side, you can see where they split off and go to the various actuators in the doors, gas flap and trunk -- isolating each branch and using the trusty MityVac is a helpful way to do it.

-Chuck

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1982 300D, anthracite grey, 260k miles, Greasecar
1999 E300D, black, 160k miles, Greasecar
2010 Honda Insight Hybrid
http://www.chuckwyatt.com
http://www.wordimpressive.com

Here's what I found when I did a search here(hint, hint)

http://www.peterschmidtransmission.com/vacuum.htm

See: http://www.peachparts.com/Wikka/Trans722VacModhttp://www.peachparts.com/Wikka/Trans722VacMod for how to check if the trans is adjusted correctly.

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I choose to be happy, even when the Mercedes is being awkward, lol

The five way splitter goes to the HVAC (green, probably), ignition shut off (brown), door locks (yellow check valve) and seat back lock (blue).
On the top of the VCV one line should go to the transmission, that's all I have as I've bypassed the egr. The line coming from the side of the VCV is a vent line that goes to the cabin.

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83 SD

84 CD

I think all the lines are going where they should. Now the car won't downshift to first. It also has the 2-3 flare but it had that before. I guess I need to get that vacuum pump and look for leaks. Any other ideas.

Defiantly check to see if transmission modulator will hold vacuum. If it does not hold vacuum, check the cap on the modulator and replace if needed.

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www.myadvoforum.com
http://advopal.com

what todd said. Also, buy a 3 way splitter (commonly found at just about any autoparts store). buy the right size and buy some extra tubing thats long enough for you to run it into your cabin with your mityvac. tap into the line going to the transmission modulator. at idle, you should have about 13" to 15" HG. that should go down to close to 0" as you press on the accelerator pedal. it has an inverse relationship to rpm.

One of my '83s had a bad 2-3 flare when I bought it. I was prepared to start sorting out the vacuum issues. A simple adjustment of the Bowden cable put it in back in the groove. I wish everything was that simple.

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John Schroader
bio burnin' 83 300D, '83 300 SD, '79 240D
"I've never met a man who was good at making excuses who was good at anything else" Ben Franklin
"You cannot permanently help a man by doing for him what he could and should do for himself" Abraham Lincoln

OT, sorry, but you have an 82, would you be so kind as to inspect the secondary fuel filter head and let us know the part number? Specifically the circled number.
Thanks.

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83 SD

84 CD