Good News !
 

Congrats & Kudos for keeping at it .

I still cannot force my center vent flat open even a tiny bit and I'm afraid of breaking it by too much force .

Lovely.

^ Quite. I've literally been battling this since you shipped it to me.

Ref post 161 mystery servo.

I don't think that's correct. There's a single page in some FSM documents that show the "Vacuum element on vent line (on vehicles with diesel engine only)".

That's part # 85 in the attached pdf. It comes off a white line, is outside the firewall, then continues on to the center pod line.

My bet on the lack of vacuum on the center pod line is a hole in the OUTER diaphragm on pod 42 - the defrost pod. If the outer diaphragm is torn, the center pod will dump vacuum through that hole. But if the inner diaphragm is intact, then the defrost vents will still move and it will still "hold vacuum" but only in one chamber.

This is the only place I've seen the depiction of the vacuum element outside the firewall. But it fits the description in post 160.

W116's have the same schematic with no element 85 :confused: Everything else is the same.

I took Norm for a full test drive today. He's been needing some SLS parts so I haven't had a full "cool down" session with him.

At night, with ambiant 84*, I hit TWENTY SIX degrees!!! I LOVE R12!!!

Still rockin' the aluminum bodied servo???

Of course! It works perfectly, I just have some vacuum leaks to hunt down. It's nice having your passenger say "it's too cold" for a change...

Just wanted to report that two months later the system is still working flawlessly and still holds a charge. Thank god!

It's getting a bit cooler here in Florida, and if it's less that 80* outside I'm getting 18* out of the center vents. Yes, you read that correctly. It still struggles above 90* ambient, but I think tinting will help. It's an old system so I'm not overly picky.

If this isn't a reason to invest in your AC system and use proper R12, I don't know what is.