Mercedes Benz repair: Non-functional climate control vaccum system, vacuum diagrams, climate control

Question
I am calling from India. I have an original american model, 300D (make 1977), left hand mercedes.  Its climate control vaccum system is not working.Please give me the climate control vaccum pipeline diagram from vaccum pump for self-servicing it. I am a technical person and intend to do it myself because mechanics here are misguiding me giving very high estimate. I shall be grateful for your expert guidance. thanks.

Answer
These links should have what you need.
Suggest you join: http://www.mercedesshop.com/shopforum/showthread.php3?t=105297


climate control vaccum
http://www.ultrahot.com/vacuum/heating_ac.jpg

Vacuum Diagrams W123 and W126 models
http://www.mercedesshop.com/shopforum/showthread.php3?t=105297