Vacuum to transmission-1980 300 SD

[Willie White]

After reading new (to me) threads on this subject I decided to see how closely my car's system comes to the Functional diagram for engine 617.950(300SD), that I downloaded from PeterSchmid.com In short, not even close. Yet all the doors and the trunk will lock and unlock; the engine will shut off;
however there is minimal climate control (the usual CC servo problem). The transmission seems to work quite well.Downshifts are absolutely smooth. Going up, there seems to be a slight delay in getting from 3 to 4 (Flaring ?)
also noted that holding the throttle absolutely still will improve shift quality.
a little too much throttle will delay all shifts too much(IMHO).The tranny has been rebuilt and the engine is in great shape. I will attempt to send the diagram of the present setup hoping someone will suggest some improvment that I might make. I hesitate to make too much of a change without some learned advice for fear I will make a giant step backward. I'M not the sharpest tool in the shed. Hope I did the picture right. Willie (Poor Soul)

[864Lightning]

I have a 79 300 SD and I found the Peterschmidt diagram to be fairly accurate. I bought the car a few weeks ago and am still in the learning process.
My trans would flare between shifts, engine kinda reving between shifts.
I disconnected the vac line to the trans modulator and this resulted in head snapping shifts. Nothing like my Lightning truck but fairly harsh.

Just last night following the MercedesShop writeups, I calibrated my vacuum control valve to have 9 inches at idle going to the trans. It was 22 inches before hand. I havent had a chance to test it yet..

As for the PeterS diagram. I have a large dedicated line from the pump to the brake booster, then a smaller line from the pump to the first rubber Y . A line from the first Y then goes down to the VCV on the injector pump. The Y on the VCV has a orifice in one leg, that leg has a white plastic ring around it.. The other two legs are free flowing, one going to the VCV and the other going to the transmission. Another line hooks to the side of the VCV and this is the atmospheric vent line from the cabin..

This doesnt answer your question much, but just wanted to add my observations.. This is a fun car to learn to work on.. A nice change from my computer controled cars..

[Willie White]

Hey lightening ; thanks for your response. when time permits I am going to try to draw the diagram from your description. I understand that the 79 300 SD and the 80 should be the same so it will be of interest to me if the diagrams are the same. Stay tuned. I note that my diagram did not get posted on the thread and I would like to seek help in getting that done. Please, can someone give the Poor Soul a clue as to how to post a picture on the thread. Willie(Poor Soul)

[dannym]

Are the diagrams from Peter Schmid the same as these?

http://www.peachparts.com/shopforum/showthread.php?t=105297

[Willie White]

Dan I dont see anything thats the same but then, mine is a 1980 116 300 SD . I didn't see that option there. Willie (Poor Soul)

[864Lightning]

http://www.peterschmid.com/vacuum/1980/617_950.jpg

This is as close as I have found. My 79 very closly resembles this diagram, except I dont have the EGR stuff so alot isnt there.

There may be one on this site,, this is a great info site for 116 bodies.
http://handbook.w116.org/

[Willie White]

Will try to post diagram again