I replaced the heater motor in this car (removal of rh fender) and then the heater core began leaking. I have been putting this off because I thought I would have to remove the fender again, but after consulting the service manual it looks like it is a pretty easy replacement all from inside the car. this is an AC car but I have removed the under hood ac with an american graphiti ac delete panel. So how difficult is this job?
You have several nuts to take off on the firewall on the engine side, and all of the vacuum and cables, then you can pull out the entire heating unit from under the dash. Put your new core in and put it all back together. It's tedious and not a alot of room to work with, but not as crazy as the fan. Good luck.
There are some tricks if you are so inclinded: http://www.v8buick.com/showthread.php?t=18080&highlight=heater+core+removal and http://www.buickperformance.com/heatercore.htm - Bill
