90 Heater Core Trouble

I am in the middle of trying to replace my heater core in my 90 Comanche. I have read many threads saying i dont have to remove the whole dash just the lower panel and the box underneath the dash. I have the lower panel removed and have removed the nuts holding the box to the firewall.

I believe i have removed all the little bolts around the box. I cant seem to get it to drop out like everyone says it will.

I have also read that if still have the AC connected then you wont be able to remove heater core until you discharge the AC. On the other hand I have seen people say they got there heater core out without removing the ac.

Any help would be appreciated. I would like to avoid disconnecting AC if possible. Still blows cold with R-12.

you need to remove the AC. You're already trying a shortcut with not removing the whole dash. I didn't remove my dash ('91), and there is no way you can get the box out without disconnecting the AC. If i was going to do it again (damn it to hell), i would take the whole dash out. I didnt keep track of the bolts very well when i took it out to replace it and it never quite went back in right. There is no easy way to do this job.

Why do you need heat in FL anyway? i say just bypass it completely if its leaking.

bdahlg said:

you need to remove the AC. You're already trying a shortcut with not removing the whole dash. I didn't remove my dash ('91), and there is no way you can get the box out without disconnecting the AC. If i was going to do it again (damn it to hell), i would take the whole dash out. I didnt keep track of the bolts very well when i took it out to replace it and it never quite went back in right. There is no easy way to do this job.

Why do you need heat in FL anyway? i say just bypass it completely if its leaking.

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Untrue, you can remove the box without removing the AC. The way to do so is by essentially removing the whole dash.

I did mine without removing the AC in my '91, and the dash was completely disconnected and moved out of the way. It was a major pain, and I would probably end up removing the AC next time. But it is 100% possible to replace the heater core and remove the HVAC box without disconnecting the AC evaporator.