Sorry Dennis that it took so long to answer.
I was working this weekend, had to switch computers and still have problems with my Internet connection. Normaly I am using an iMac Apple but I had to buy a PC as well to read the EPC from MB...
The worst thing is I can't find what you are asking for!
The EPC takes some time to understand! One never knowes where MB put an item. As your switch-over valves : are they under FG (chassis) in group 54 Electrical equipement and instrument , 80 Vacuum system , 82 Electrical system or under M (engine) at 07 Injection or 14 Intake and exhaust manifolds (found partly my vacuum system there!) ? I also checked under GA 27 MB Autotranny...This last one is very interesting as it gives schemas but only information about fittings, elbows...But I saw your dual switch-over valves there.
The worst of everything is that I can't even find my own vac system : when I found something resembling than I got a
"Callout non valid with this BM". Resembling yes : there seemes never to be exactly the same system in a car and the EPC...
Fortunately, next sunday my friend and MB-indy promised me to spend the entire sunday with me to learn me the EPC !