Black tank sagging

[FBB]

My 2019 Isata 5 black tank has developed a 3" sag down from the floor. The mounting clips are secure and this is a curve in the tank itself. The top of the tank is also badly deformed with one side of the rubber gasket being 3/4" lower than the other. All of this came to light after having a leak caused by the 3" pipe coming out of the rubber flange while traveling on steep and somewhat bumpy roads. While I have replaced the toilet flange with a longer pipe it is still my concern that this movement of the top of the tank while in motion with tank contents sloshing and causing movement of the tank top, this may not be a permanent solution. Because of the tank top not being stiff, it was not possible to get the pipe all the way into the rubber flange. I would have to say it appears to be an engineering failure and I would appreciate any help. I have seen various comments on changes to this tank design and fittings. Looking for any information on a permanent solution.

[FBB]

There is also a 1" sagging in the gray tank but no leaks....yet.

[bikendan]

Moved thread from the Tech and Repair section to the Motorhome section's Dynamax sub-forum for better help from other Dynamax owners and possible factory support.

[bclemens]

I would say a replacement tank. Sometimes, the supplier will pull the tank too early and it is still warm. Sometimes, it can sag a bit, which then amplifies over time.

[FBB]

Originally Posted by bclemens

I would say a replacement tank. Sometimes, the supplier will pull the tank too early and it is still warm. Sometimes, it can sag a bit, which then amplifies over time.

Do the new tanks have a different connection mechanism for the vent and toilet?

[bclemens]

They "can". We spin weld in a threaded connection today to prevent any separate...at least on the vent. I don't think we can do that on the toilet so it is still a rubber slip fitting.

[FBB]

We have found that the original tank is no longer available and a workable replacement would require plumbing reconfiguration. Also a 4 to six week delivery timeframe doesn't work very well while we are on the road. So I removed the toilet and placed a pipe clamp on the rubber flange above the tank. I reinstalled the drop pipe and worked it in as fully as possible. The pipe was a good two inches in and using the space of the sag between the tank and floor, I was able to tighten the hose clamp providing a solid mechanical connection. I also cut wedges and placed them to keep the tank from moving any more. Feeling like this is a permanent solution to a bad situation.