Black tank falling out!

[Don F]

Our black tank has dropped between the rais that hold it in the frame. The vent pipe broke. When we were dumping we instantly knew we had a problem. Took the underside panel off and the tank was bowed in the middle. Built a support panel and jacked the tank back up so we could dump. We have had a stretch of 90 degree plus days. Any suggestions or experiences. I can fix by getting 3-4 supports from frame member to member and correct the problem. No we weren’t towing. Have been parked in one location for 4 plus weeks. Always start towing cleaned out when possible. Thanks. 2015 41BR

[RomanyLife]

How awful! Don't have any advice, sorry to say. We have our belly open getting ready to install electric valves and plumb the two grey tanks together. First thing we noticed was the precarious mounting of the tanks... but then have learned that it is pretty typical. Seems like a very small amount of contact for the weight of a full black tank. ALSO notice that ALL of the tanks bow a LOT between the cross members. We hope this is normal, but it is a little disconcerting for sure. Curious if anyone has had problems with tanks coming loose?

[NW Snowbirds]

I did not like the bulging Corplast beneath the tanks and hearing about how others have lost their tanks. In fact, we lost about 8 ft of Corplast on the first trip. To remedy the problem I bolted 2x2 angles to the main frame members beneath the Corplast in the bulging areas spanning the width. The exact length needed (I think 5 ft) is sold at Home Depot. It is easy to drill bolt holes in the flanges of the main frame on each side and secure the rails with nuts and bolts.
Also relatively inexpensive fix/preventer.

[Shane Wood]

My black tank fell off the cross members and put a hole in it. When I replaced it I put 2- 2" ×3/8" steel stock across the cross members tying them together. The cross members that the tank sits on spread out causing it to drop.also glued carpet to the side nearest the tank to keep the tank from getting a hole worn in it. The bottom of th tank is v shaped so it looks bowed but is not

[RomanyLife]

Yes, Todd thought maybe adding some steel under the tanks might be a good plan. Actually, the FW tank seems to bulge the most and it has several cross members already. Odd. Putting the carpet on to protect is a good idea too. We will have to give this some thought before we finish the job, I know I will have terrifying visions of those bulging tanks forever as we travel... Lord, it's always something. We usually travel as empty as we can, but as frequent boondockers, it's simply not possible to travel that way all the time. We either have a full FW or full grey/black tanks. This is the reason we upgraded our suspension, wheels and tires, and we are still right up to the limit. Frustrating, but that's RV life. It keeps me from shopping LOL.
~Theresa

[Don F]

Thanks to all the comments. I worked on the ABS piping today and fixed that. Thought of using pieces of steel to support the tank. Great advice! Enjoy the travels.