1987 560SEL
Ther is a "valve" which is located next to the fuel distributor on the manifold on the drivers side. It had three connections. One is a smsll vacuum connection in front, two in back which go connected via what appear as "high pressure line" to the a/ c high side (I think high side" line. the two high pressure line (asssuming high pressure as they are both steel and heavy rubber) are aboutmuch larger than normal vacuum line, probably about 3/8 inch in diameter and about 12 inches long.
#1 What is this valve?
#2 Are these two line r-12 lines or are they huge vacuum lines which terminate into a valve in the a/c line?
John1