Sounds somewhat like an problem we had with the fresh water tank.
After hitting a few good bumps on rough part of the freeway we had leaks.
Ended up replacing the fill pipe\tubing because it had split.
Then the vent and drain hose clamps had gotten disturbed and were dripping.
Took a bit of crawling around under the trailer to remove the insulation panel underneath.
I wouldn't say it was extremely difficult to do at least on our fiver.
Had a creak\squeak under the bathroom on our current rig that ended up being a heater vent.
Some expanding aerosol foam around the ducting fixed that.