Vacuum Leak - 500SEC
After an extended period of inoperability, I had the A/C compressor, evaporator, etc. replaced and the system converted to R134. As an apparent result, some new issues have revealed themselves.
Firstly, the "economy" guage needle is touching the red zone at idle, indicating a vacuum leak in the system. The vacuum elements for the recirculation door appear to be inoperative, and the defrost door behaves curiously. When partial defrost is selected (upper and lower arrows) faint cool air movement occurs at the windshield and center vents. If "normal" mode is selected, volume at center vents increases until a load is applied to the engine, at which time, all air from center vents disappears and will not return, even when totally backing off the throttle. Selecting partial defrost again starts the process over.
It seems apparent that a vacuum leak exists somewhere. One or more of the under-dash vacuum elemts may be faulty, but I hesitate to repair/replace until I am confident that a vacuum leak elsewhere is not the culprit.
The engine starts, idles normally, which indicates that the vacuum leak is not affecting the air mixture, etc.
Any thoughts on how I should proceed?