Thread: Evaporator Core leak

When I did my heater core Im pretty sure I caught a glimpse of it, further up.
How do you know it is the core?

Here is a link with the layout.

http://parts.nalleygmc.com/showAssem...rimLevel=25592

I did a sniffer test and it only showed the leak coming from under the dash near the evaporator core. My luck it will turn out to be a stupid o ring. The car had sat a long time before I bought it. I replaced the ac line that comes off the fire wall to the dryer because there was a section that had been worn through by the transmission shift cable that someone routed it on top of, move that too so no longer an issue.