As luck would have it, my heater core developed a leak. Fortunately getting the under-dash encasement removed was not as hard as I thought or as bad as the FSM made it out to be (There was now way I was pulling the dash-pad and tearing the ducts out as recommended). The core itself is overall in good condition, minus the small pinhole that can be easily fixed (thankfully). While I have the majority of the climate control system pulled, I was wondering if there's anything else I should look at or service while it's out? The foam on the doors is severely degraded and at the very least needs cleaned off. Is it worth going through the effort replacing?

Additionally, this is also a Tempmatic equipped car. I'm unsure if the its operating as intended as while it seems to maintain temperature when set to around 70, increasing it above 70 just causes it blast 90-degree air at you, regardless of cabin temp. Are there any things I should look at for defects or parts I should replace on the Tempmatic unit itself?

 

Verify the condition of the vacuum hoses going to the AC control head. GM used vacuum hose with a colored stripe to control air doors in the plenum. If these are rotten your AC won't work right even if you have a full charge of R12.