1. Contac Lance and the NHTSA immediately with your pics. This will probably result in a National Safety recall. Which means you will get a NEW line at no cost to you, parts and labor. If yours has this, all other with your model will have it. You will be saving scores of RV'ers a major problem and possible explosion or death.
2. From the pic, it appears not just discolored, but has rubbed off part of the copper and the integrity is compromised. I would replace that line if it was mine. Doug
PS, this is how recalls get initiated---when the customer finds a problem and notifies the authorities.
