VintageMopar wrote:
It keeps hvac doors from changing under low vacuum conditions like accelerating. It may have a one way valve built in on large (input or manifold) port, other wise there is one in the supply hosesmall one goes inside vehicle.
It doesn’t have HVAC, only factory heat, and the doors are cable controlled. I do have factory Cruise Control, so maybe it’s for that, but the nipple on the Cruise Control servo is much bigger than the tiny reservoir nipple.
Or, maybe it was for the EGR and vacuum amplifier?
