I finally found the insulated line that typically failed above the exhaust. I am trying to think of creative ways to remove the insulation without dropping the exhaust. Do you have any? 90* needle nose pliers? If I score the insulation with a razor, would I be able to peel it off with just my hands??No, his line cracked similar to the OP's, near the height control valve. He posted the pictures on one of the AHC failure threads but I can't find it. His line wasn't rusted and it didn't show any obvious reason for failure. Similar to the OP failure of this thread. This why I mentioned that he should check the lines going into the height control valve.