just me wrote:
Why do you carry a full black holding tank and then take it to have work done on the trailer? More weight up front.
Oh please. Are you serious?
Our trailer stays at our home and we just had guests for a week and the adults used the trailer. I hadn't had a chance to empty the holding tanks yet. It wouldn't have avoided the problem, just the mess. I wouldn't even had know until we were on the road and away from home!
Even if I had flushed the tank before the work it would have been 3/4 full of water. So what's your point here?