Seneca Fresh Water Tank Support System

[McGintys924]

This question goes out to all of you who have added supports for the fresh water tank. Getting my tank out was, or course, the easy part. Unfortunately, as is the case with many of us here, that tank is malformed from the complete lack of support underneath it; it has a large bulge on the bottom and is caved slightly on top. I did construct a support structure underneath with 2x4 and 5/8 plywood. Unfortunately, placing the tank back in atop this support proved daunting this afternoon. In fact, it was down right impossible. The main problem was the wires and plumbing that existed in this compartment. I did try tapping these items to the ceiling of that bay but the angle required to replace the tank over the new support system resulted in contact with those wires.

An attempt to abort the support system entirely and replace the tank normally resulted in the plumbing at the rear of the compartment being in the way with no foreseeable means to raise it above the tank as the tank was pushed in under those lines.

I would like to ask if anyone has any insight on this issue or words of wisdom. I am actually pretty concerned about the issue of replacing the tank at this point.

[McGintys924]

Finally got the tank up in there, but would still like to hear of people support systems for under the tank.

[Les7h]

Jayco motorized in Middlebury In put wood 2 x 4s between the frame and thermoplastic ( under warranty ) and it works but the same people put a nice metal frame under Robby’s and I like it much better so I plan on building a metal frame and attaching a storage for a sewer tote and maybe a spare tire mount ( another idea from Robby ) Les

[Mark S]

I put three rigid 3/4” emt electrical pipes under the tank and on top of the frame. The weight of the tank holds the pipes in place and there are no sharp edges to dig into the tank. Seems to be working. There is no sag in the tank. Quick and easy. I may some day build a more elaborate system, but for now this works.

[Rustynuts]

I just got done doing this but I had a different situation than others I had read about......I have the 2018.5 S2RV with the 100 gallon fuel tank right under the section with the water tank in it. I only had 3/4” between the frame rail and the plastic compartment bay. I used 3/4” x 1.5” x .120 wall rectangle tubing cut at 36” long. The frame rails are 34” wide so this left 1” sticking out each side so I could screw on 1”x1” angle which locked it in place. I battled the issue of getting the 36” pieces in position as there were fuel fill lines and vents, wire looms and hoses running between them but after about an hour working with a pry bar to lift the plastic compartment up, I got them in. I was shocked by a few things I found in the project like a propane hose ran over the the top of the frame rail so when the water tank was filler, it was smashing the propane hose. Also the wires that ran on top of the fuel tank ran over a U channel frame brace so when the water tank was full, it was over 500lbs smashing the wires into the 1/8” edges of the brace which over time would have been damaged. It was a long project that also involved insulating every water pipe I found, removed macerator and redid the plumbing, adding heat into the wet Bay Area and sealing all the holes I found.....but it was worth it and I know it was done right.

[Rustynuts]

I just got done doing this but I had a different situation than others I had read about......I have the 2018.5 S2RV with the 100 gallon fuel tank right under the section with the water tank in it. I only had 3/4” between the frame rail and the plastic compartment bay. I used 3/4” x 1.5” x .120 wall rectangle tubing cut at 36” long. The frame rails are 34” wide so this left 1” sticking out each side so I could screw on 1”x1” angle which locked it in place. I battled the issue of getting the 36” pieces in position as there were fuel fill lines and vents, wire looms and hoses running between them but after about an hour working with a pry bar to lift the plastic compartment up, I got them in. I was shocked by a few things I found in the project like a propane hose ran over the the top of the frame rail so when the water tank was filler, it was smashing the propane hose. Also the wires that ran on top of the fuel tank ran over a U channel frame brace so when the water tank was full, it was over 500lbs smashing the wires into the 1/8” edges of the brace which over time would have been damaged. It was a long project that also involved insulating every water pipe I found, removed macerator and redid the plumbing, adding heat into the wet Bay Area and sealing all the holes I found.....but it was worth it and I know it was done right.

[RVermont]

As always great mod.
I had similar issues getting the tank back into the compartment after adding the support the water heater hoses kept getting jammed behind the tank. Had to tape some flat straps to ceiling. These acted as rails and kept the hose up. PIA project but now feel more comfortable driving with full tank of water. Surprising that an engineer would have signed off on the current design. Leaving 8 inches of a flat tank completely unsupported seems like a issue waiting to happen.

[McGintys924]

Agree that replacing the tank turned me into a sailor (choice words uttered repeatedly). Liking your idea Rusty; this summer I will be pulling the hot water tank and water tank to heat tape and insulate all those lines and place a heater pad underneath the fresh tank. No way I can get the water tank lines heated with a space heater to survive these Illinois winter temps!

I ended up doing a carpeted double ply of plywood (running criss cross) to support the tank and this has worked well. Forgot to take pictures before reinstalling.

[Rustynuts]

Originally Posted by McGintys924

Agree that replacing the tank turned me into a sailor (choice words uttered repeatedly). Liking your idea Rusty; this summer I will be pulling the hot water tank and water tank to heat tape and insulate all those lines and place a heater pad underneath the fresh tank. No way I can get the water tank lines heated with a space heater to survive these Illinois winter temps!

I ended up doing a carpeted double ply of plywood (running criss cross) to support the tank and this has worked well. Forgot to take pictures before reinstalling.

I added a heat duct to the wet bay compartment which also has my water tank. Right above the compartment door with the propane tank I had a 6” already cut into the floor from the factory and all I had to do was cut the linoleum out and a tee in the heating duct under the bed. Where the duct came through I used an under eave dryer vent as it has a built in damper, screwed it up to the floor and connected the duct and it faces toward the drivers side and blows along the water tank and onto the back of the Nautalis panel. Another 37K owner said he looked and already had a heat duct into that area from the factory....so who knows.

Some other interesting things I found while under the bed was crushed heat duct lines which is why we had bad heat flow to the back and totally bare and un-capped wires from the solar panel wires which of course were setting right above a metallic foil duct...

[DaveT]

Always seemed like a very sturdy solution to what you're dealing with.

[mcdanger]

Has anyone had any contact with Jayco about the sagging fresh water tank? I have not seen any posts or have possibly missed any about a response from Jayco. We have a 37HJ due for delivery in Orlando 2/22/2019. MLK birthday on Mon. so I will call Jayco today. I am concerned!

[RVermont]

There was a earlier post on a different thread that mentioned the poster contacting jayco and being told that the tank and supports were within engineered specs. I decided if that was their answer it was simpler to fix it myself then to drag it back to the dealer and have them fix it. Let us know what you find out.

[Robbbyr]

Originally Posted by mcdanger

Has anyone had any contact with Jayco about the sagging fresh water tank? I have not seen any posts or have possibly missed any about a response from Jayco. We have a 37HJ due for delivery in Orlando 2/22/2019. MLK birthday on Mon. so I will call Jayco today. I am concerned!

While I was still in warranty I took my unit back to Jayco to have several items repaired, one of which was my sagging freshwater tank. Jayco installed rectangular steel tubes spanning my frame rails under the compartment supporting the tank. That solved my sagging issue. So yes, Jayco has a fix!

I carried their repair even further myself by doing the same things under my black and gray tanks. Then I used rigid foam panels under those tanks to take up any "gap" underneath them and also to provide some insulation.

[Robbbyr]

Here is a link to a prior thread where I included some pictures of my new tank supports: https://www.jaycoowners.com/forums/f...g-59526-2.html

[tpastorini]

So I did my tank supports over the weekend. Gotta say pretty easy. There was a 3' x 4' x 1" piece of styrofoam under the tank which was deforming it to begin with. Before I did the support I measured that I was able to fit 64 gallons into the tank. Figuring that I would be able to put more in after I finished the supports, I filled it again and got it to fit .... you guessed it 64 gallons. Brochure states 84 gallons including hot water heater which is tankless so tank is 0. I looked at the tank after it filled. It was nice and square and no deformity. Is it possible the last owner switched the tank? I doubt it as there was no evidence of replacement that I could witness. BUT, the last owner did swap out the tankless water heater for a tank version. Either way the job is done and I can relax better going down the road with the support in place.

Thanks to the group for letting me know about this problem, would never have caught it.

[memphis02]

I did the same math and came up with approximately the same total capacity, this weekend, which made me scratch my head as it was at odds with what Jayco claimed. I, then, used a flow meter w/ totalizer and got 64 Gal. We're definitely getting shorted a few gallons...

I was thinking about trying to slide some 2x6s between the tank and frame rails to fix my tank's sagging but wasn't sure it would work.

I'm glad to see I'm not the only one dealing with this problem, today!

[tpastorini]

I feel way better. I used 4 feet of 2 inch angle iron times 4 of those and a sheet of plywood under the tank. Took about 50 minutes. I didn't think the plywood alone was enough.

[ebarchak]

Originally Posted by Rustynuts

I just got done doing this but I had a different situation than others I had read about......I have the 2018.5 S2RV with the 100 gallon fuel tank right under the section with the water tank in it. I only had 3/4” between the frame rail and the plastic compartment bay. I used 3/4” x 1.5” x .120 wall rectangle tubing cut at 36” long. The frame rails are 34” wide so this left 1” sticking out each side so I could screw on 1”x1” angle which locked it in place. I battled the issue of getting the 36” pieces in position as there were fuel fill lines and vents, wire looms and hoses running between them but after about an hour working with a pry bar to lift the plastic compartment up, I got them in. I was shocked by a few things I found in the project like a propane hose ran over the the top of the frame rail so when the water tank was filler, it was smashing the propane hose. Also the wires that ran on top of the fuel tank ran over a U channel frame brace so when the water tank was full, it was over 500lbs smashing the wires into the 1/8” edges of the brace which over time would have been damaged. It was a long project that also involved insulating every water pipe I found, removed macerator and redid the plumbing, adding heat into the wet Bay Area and sealing all the holes I found.....but it was worth it and I know it was done right.

I think I know why this problem exists. Jayco never redesigned the molded compartments for the S2RV. The frame rails are about 4 inches lower on the S2RV. The side compartments are the same height off the ground, but the rails are lower. In the M2 my guess is the molded compartments sit right on top of the rails with no sag.

I have the same issue on my 2021 37TS. The gap on mine seems to be more like 4 inches. It is at the dealer right now and I am worried about what they are going to recommend. I also have the problem with my black and gray tanks. I placed lumber under the tank to lift so it was not completely loose.

[Rustynuts]

Originally Posted by ebarchak

I think I know why this problem exists. Jayco never redesigned the molded compartments for the S2RV. The frame rails are about 4 inches lower on the S2RV. The side compartments are the same height off the ground, but the rails are lower. In the M2 my guess is the molded compartments sit right on top of the rails with no sag.

I have the same issue on my 2021 37TS. The gap on mine seems to be more like 4 inches. It is at the dealer right now and I am worried about what they are going to recommend. I also have the problem with my black and gray tanks. I placed lumber under the tank to lift so it was not completely loose.

This is also an issue on the M2 chassis for many people