I have a 2003 3670RL that seems to want to leak where ever it possibly can. I recently patched the cracked black water tank with Plasti-Mend and have to wait until next season to see if it was a success. I believe it went well. While putting some tools away I found the tray under the hydraulic pump full of oil. I researched the problem and it appears to be rather common. There is a lot of mentioning of replacing an O-Ring. (But How?) Some of the old posts have pictures but they no longer work. So I'm wondering could it be a simple as removing the four bolts that hold the plastic reservoir tank to the metal part and replacing an o-ring that sits between them? (I doubt it)
If you drain the tank first I see no reason why it wouldn't work, but you should be able to find a lips heel on the lippert website that details this issue.
2012 F350 6.7 L dually, 2013 3800RE with 6 pt leveling, Sumitomo 17.5" load range h tires, Samsung 18 cu ft residential fridge, 8k Morryde I.S. with disc brakes. Full timing since 2012.