Im pretty sure it's a line. Just don't feel like crawling around it right now. Just did the rear brakes and lines on my CJ7 and as soon as I got it firmed up, popped the front line. Anyways we are looking at 6"-10" of snow tonight.
Theres 3 small bolts holding on the thermo cover. Be careful not to break them! I got away with just two bolts after I broke one. Its right up front-easy to get at.
These things take forever to warm up at idle-you probably wouldn't get any heat blowing for 15 minutes or so.
__________________ Don't make a fuss-just get on the bus!