So my 93 Cherokee that i'm trying to sell has a bad heater core. Probably. The po has it bypassed. I want to fix it to try and make it easier to sell in the winter. I'v done heater cores in other cars but never a Cherokee. The only problem i'm having is that It looks like I have to disconnect the a/c to get the heater box out. That wouldn't normally be a problem because My work has a a/c machine, but the 93 uses r-12 and we can't work with that. I wouldn't normally worry about it but the a/c is ice cold and works great.
So my question is... Is there any way to replace the heater core without draining the a/c?

 

Unfortunately no. R12 is a much better refrigerant than 134a, but only large industrial cold rooms can legally use it. The biggest cold storage units use anhydrous ammonia, but that stuff is real nasty! Maybe you can find a heavy industrial company that can evacuate the system for you, then you can put in a change-over kit to 134a. It won't get as cold as R12 though. When I was still working at the plant, I knew a guy who worked in refrigeration. When the changeover was mandated, he was allowed to use up any R12 he still had in inventory. AND he had a lot! BUT this was over 20 years ago. I doubt anybody has any left now. Maybe.