Alright, I took my time and over the last few days I pulled the HVAC box out, then I took a wire wheel to the firewall where it mounts and got rid of all the old sealer and crud that had been built up. I repainted the area matte black to match the rest of the bay. Then I went through the HVAC system. I replaced the defective heater core, A/C evaporator, Accumulator, and orifice tube and all related seals. (All under warranty). I also warrantied the compressor because the clutch bearing was making noise. Then I put all the pieces back together and used 3M strip caulk to seal every possible leak area. I also replaced the foam between the heater box and the interior side of the firewall with new closed cell sealing foam. Then for the A/C box on the front side, I used generous amounts of 3M strip caulk and thoroughly sealed the entire assembly together against the firewall. Rain should never leak in that area again!
All apart and the firewall restored:
And back together:
Heater box partially re-installed:
My wife has been working on the upholstery while I've been dealing with the HVAC. She is still working on patterns and pieces so nothing too exciting yet, but she did finish these panels that will be part of the rear bench. I'm getting excited for how this will turn out!
Don't mind the marks, that's just excess marking chalk that needs to be cleaned off:
I'm trying to work on the headliner now.. I wish I could flip the van over and work on it upside down lol. 4 friends had a hard time holding the 12ft long panel in place to try to get it trimmed correctly!