Volvo: volvo hvac, vacuum lines, rear heat

Question
We have not been able to find a vacumm diagram of the havac controls for a 87'240DL manual A/C. Repaired vacumm leaks, but am not sure that the mode switch is plumbed correctly. floor/recirculate does not switch with floor or recirculate buttons.

Answer
Tom,
Where the dash vent ducts run across to the far ends there is a vacuum diaphragm. There are ones on the climate case for the rear heat. There are also ones for the defrosters one left and one right. You can see the vacuum lines going to them. The large mode switch controls where all the vacuum goes. There is a reservoir on the center hump that is used to store vacuum and a line that comes in from the intake manifold to supply the vacuum.