AC evaporator core replacement

[liftedz71]

i have a 97 obs that needs a new evap core and iam having a hell of a time getting into the black box underneath the dash. I have completely removed the lower half that contains the heater core easily. However i cannot get the other half that contains the evap core to fully release. Im not sure but it seems like the floor vents are connected to the half i need to remove, but its just hard to tell. If anyone has successfully removed this HVAC box and has an idea how it comes apart please let me know. Otherwise i will be trying the dealership for a diagram.

[oldred95]

The top section bolts to the firewall from the outside in. In order to get it out I'm almost certain the dash will have to come out, at least part way. I put an evaporator in an 05 Yukon and it took about 6 hours total but I've had a few NBS dashes all but out before too so I knew what to take loose. Its no fun thats for damn sure. Is the evaporator leaking or what seems to be the problem? Evaporators almost never go bad. I had to replace the one in the yukon because the customer said the AC smelled when the AC first turned on. I hope you have a better reason then that.

[liftedz71]

yea i just got it taken care of late yesterday. Actually the nut on the evaporator that connects to the drier was seized and i twisted the aluminum pipe off. It was not fun getting to the evap core at all. PITA, But i now can hang beef in my truck.....worthwhile.

[oldred95]

There's an army trick for that. Get two smaller hammers and smack the nut thats made onto the dryer from both sides at the same time. Do that a few times and it will break the rust and corrosion loose and it should come right off. I guess that will be for future reference since you already got yours replaced.

[liftedz71]

yea i thought about that after the fact but it works great now.