2016 Montana holding tank question

[Hedgehog]

I have a 2016 Montana 3160rl Legacy and had a quick question about the holding tanks. I currently don't have any issues or leaks that I know of. My question is what holds the tanks in place? The reason I ask this is because I notice the black corrugated plastic that encloses the underbelly is bowing down in certain spots in front of the axles. When you press up on the plastic at the very front of the camper, it sounds and feels like there is loose debris on top of it. When you press up on the plastic around the area where the metal crossbars are located, it feels like it could be the tank that I'm pushing on. Is this normal? Is it only the metal crossbars that hold up the tanks? If I want to take the corrugated plastic down, how do you remove the fasteners ? Am I worrying over nothing?

[tspoon]

If You remove the wall in the basement you can see the tanks. I had a lot of junk on and under my tanks. Just remove the screws on the bottom cover to lower it down.

[Hedgehog]

I did remove one side of the crossbar and peek above the corrugated plastic, it was wet under there but I'm not sure if that is a leak or from driving in the rain. I've been caught twice in the past week in heavy rains while traveling.

[MARK A]

Originally Posted by Hedgehog

I have a 2016 Montana 3160rl Legacy and had a quick question about the holding tanks. I currently don't have any issues or leaks that I know of. My question is what holds the tanks in place? The reason I ask this is because I notice the black corrugated plastic that encloses the underbelly is bowing down in certain spots in front of the axles. When you press up on the plastic at the very front of the camper, it sounds and feels like there is loose debris on top of it. When you press up on the plastic around the area where the metal crossbars are located, it feels like it could be the tank that I'm pushing on. Is this normal? Is it only the metal crossbars that hold up the tanks? If I want to take the corrugated plastic down, how do you remove the fasteners ? Am I worrying over nothing?

I found an extra tank crossmember up in there on my 3610😳 Nothing to worry about I suppose unless you have the unit that's missing one. I have it!!

Mark

[1retired06]

Underbelly is held by outside cross braces that unbolt, and self tapping screws. Not hard to pull down and if yours is like mine, two piece, front and back. When I pulled mine off to rerun plumbing lines, I found wiring harnesses, cable pulls for the tanks, and other crap laying loose on the bottom. I even founds chunks of wood, sawdust, cuttings floating free under there. That may well be what you called debris that you felt.

[Theunz]

I just replaced a bad grey water gate valve cable on my 2015 3100rl and the coroplast on mine is attached by pneumatic nails. Most of the nails came out easy by just prying with a big screwdriver, however a couple of them required a small nail bar. There is a steel frame around the tanks which holds them up, and the exposed bars under them don't even touch the tanks, at lest when they are empty. I drilled the empty nail holes out a little and replaced them with self tapping screws. Not hard at all, just a little time consuming. Also found lots of construction trash in mine also!

[rohrmann]

The metal braces under the coroplast belly do not support the tanks, just the belly material. Last year, I had a leak in my grey tank, and after making the repair, I added two additional angle iron braces, so there would be a brace every foot under the tanks, and then installed blocking under the tanks so they would have support from the braces. The tanks have a slope in the bottom, 1/2" per foot so they will drain toward the drain valve. The photo below shows where I glued blocks of styrofoam and a 2 X 4 in one position above the coroplast to the tanks and above the braces. The tanks do not sag now, even when full.