Paul, when I had the 02 Journey, one of the lines going to the rear slide mechanism got partially melted since Winne mounted it too close to the exhaust. I could see the line sitting on top of the frame rail above and near the muffler so you might check there. It was a long line that went from the ram all the way back to the pump, maybe 22'. I had a new line made up at a local auto parts store that had the equipment to make up hydraulic lines. It was a greasy, nasty job to replace.
The other location for lines is in the space below the removable wood panel just under the foot of your bed (space behind your electrical panels). If you remove that panel at the top, you can easily see the main slide ram and the lines going to it. I don't think those would have been affected by your exhaust leak but you could still have a leak at one of those fittings.
Good luck.