NC928S4

Recently a hiss started that was audible when idling and then prominent after engine was turned off as it the vacuum came back to ambient pressure. Controls for vents seemed to have no effect on airflow direction and this explains why. Below is the picture of what I found.

The rubber vacuum rail that connects the HVAC solenoids had a crack. I expect I'll need a new one but decided to take a crack at gluing it back together. I used 3M Super Trim Adhesive on interior crack surfaces and then a coat of gorilla glue on the surface. I kept it closed in a slightly compressed C-Clamp until it dried. In addition to age I believe the crack was accelerated because the tie wrap bundle holding all vacuum lines was causing a bending strain where the crack occurred.

So far vacuum holds and all vent controls are working.