Heater Core & Evaporator Replacement
Here's how I spent my week off work during Christmas break: replacing the heater core and evaporator on my 1995 Tahoe 2 Door Tahoe!
Whew, what a job.
I had an A/C refrigerant leak I couldn't pin down, and I also had not been happy with the air flow out of my dash vents for quite some time (always felt like there should have have been a lot more air movement coming out the vents). I decided after 419K miles, it was time to replace the original heater core, evaporator, and condenser (A/C compressor is fairly new).
I removed the entire dash assembly, and then the HVAC box:


HVAC box removed:

The original evaporator was packed full of nearly 30 years' worth of dirt and debris:

And upon disassembling the HVAC box, I discovered that all three main blend/mode doors were in terrible shape; most of the rubber sealing flaps were completely gone:

Here's a comparison of one of the old doors against the new door. You can clearly see how the new door has a rubber flap all the way around that the old door no longer has:

New heater core and condenser (forgot to grab a pic of the new evaporator):


New condenser going in:

I also replaced the hard line going from the evaporator to the condenser, and of course a new drier.
I also took the time to replace all three electric actuators that open and close all the blend/mode doors.
While I wasn't looking forward to this job, all in all, it really wasn't all that bad. I took my time and was not in a hurry, so I didn't feel stressed about how long my rig would be off the road. I started the day after Christmas, and finished up this past Saturday after New Year's; and that included taking 3 days off for a mini-vacation with my wife!
I still need to vacuum and recharge the A/C system, but everything is else is back together and working properly.
With a new, clean evaporator and new blend/mode doors, there is much improvement in the amount of air moving through the dash vents.
Casey
1995 K1500 Tahoe 2 door, 6.5LTD, 4L80E, NP241, 3.42's, 285/75R16 BFG K02's; 1997 506 block; Kennedy OPS harness, gauges, Quick Heat plugs, and TD-Max chip; Dtech FSD on FSD Cooler; vacuum pump deleted, HX35 turbo, Turbo Master, 3.5" Kennedy exhaust, F code intake; dual t/stats, HO water pump, Champion radiator; Racor fuel filter