FRESH WATER TANK LEAK

[94-D2]

I’ve owned my 2017 Big Horn for three years now. This last August, we had a serious red flag fire warning weekend complete with a PGE Public safety Power shut off. In light of that, I filled my fresh water tank (30-40 gallons) in case we needed to evacuate. Following an all clear, I left the tank full, just in case. In October, I pulled the trailer for a week in South Lake Tahoe CA. Perfect weather and full hook ups. Still had a full fresh tank on board. On day 2 of Tahoe, I noticed a rather large fresh water leak from various points in the undercarriage. I assumed the fresh water was leaking and traveling through the coroplast under the trailer. After three days it stopped. I suspected there was a possible crack in the fresh tank since we had a tire tread incident on the road in February, and a slight showing of water at that time. Upon leaving the resort in Tahoe, I found that the 12v pump didn’t not charge the water system while on tank mode. When I got home, I discovered the fresh rank was in fact empty. I never drained it and concluded it drained o it’s own, and whatever damage was suffered from the tire tread incident was greater than expected.

This last week, I removed the coroplast from the undercarriage of the trailer. What I found disappointed me, but I expected it nonetheless. The bits and pieces of the internal workings of this trailer were haphazardly thrown Together by a kindergartner and as it turns out, caused a water leak in the fresh tank by shoddy workmanship that had nothing to do with the tire tread Was hit on the road.

The fresh tank was installed in its usual fashion. A cross member at one end and three steel straps perpendicular to the cross member. As such, water supply inlet/pump draw tube and low drain hose Were installed and plastic welded next to each other at the bottom of the forward facing side of the tank. Upon filling the tank to capacity for the first time and traveling, caused the tank to bulge on the bottom between the steel straps thereby stressing the welds for the inlet supply fitting that was shoddily welded into place. This caused the weld to fail and produced a leak that drained the tank in three days.

This is the way I found the undercarriage after dropping the coroplast.

[94-D2]

I would have thought it would come with insulation. But I guess I’m beginning to understand why it was such a great deal.

[alboy]

Interesting,ours has the bubble wrap as well but was well insulated.I replaced with r22,we are wintering in it and it stays very nice,it has the winter pkg .

[94-D2]

Only insulation in there (if it is even that) is a metalisized bubble wrap laying on top of the coroplast. Nothing else.

[alboy]

Replace your insulation with Rock WOOL AS ITS WATER IMPERVIOUS.Had the ice maker line let go on our 2014 Landmark,the wiring etc was very neat.Also check the heat ducting for crimping.cheers

[94-D2]

blueglide wrote:
Good job! Those fresh water poly tanks are usually LDPE (low density polyethelene) and plastic milk jugs (or water bottle caps) will often work if you don't have LDPE welding rod.

Apparently so. Been holding a full tank for several hours now. I’m going to coat in a uv activated plastic weld and re-install the tank with some additional belly support. I will clean up the wiring and hydraulic lines and close backup with the coroplast covering. I also have a mod planned for the rear bumper and going to add a set of casters that will require modifications to the brackets of the rear end with a 92” custom diamond plate storage box.

I’ll post up some pics as it gets done.

[blueglide]

Good job! Those fresh water poly tanks are usually LDPE (low density polyethelene) and plastic milk jugs (or water bottle caps) will often work if you don't have LDPE welding rod.

[94-D2]

I borrowed a proper air welder today. It came with three different types of rods, abs, pvc and PP rods. None of those would stick. I deduced that this tank was PE plastic and I enlisted a few tops from cheap water bottles. Worked like a charm. Tank is full on a set or saw horses, no leaks from the weld in over three hours. I’m going to over coat with UV activated composite weld and call it good. If it happens again, I will try a direct replacement from the manufacturer if that is possible.

[Lantley]

94-D2 wrote:

Lantley wrote:
I sort of had the same issue. Basically a poor installation. I replaced the tank myself with a brand new tank. I did not trust that a repair would be permanent or foolproof vs. replacement.

I found the model but a new one does not come with the inlet, drain, over flows and monitors in.

Did your replacement come prepared or did you have to have them custom installed.

Interestingly enough, I ordered mine through an RV shop. vs. directly from tank manufacturer. As a result all those items were in place. I imagine the shop knew to have tank prepped before it was shipped vs. just ordering a blank tank.
Kudos to the shop because I would not have thought about ordering the tank prepped. For the most part I think I could of transferred old connections to new tank. However it was nice that it was already done for me . Especially tank sensors.
Although the shop ordered the tank. The tank was shipped directly to me ready to go. Cost through shop was comparable to ordering directly.

[ksg5000]

No expert but FW isn't under pressure and something like Eternabond might suffice. Won't cost much to test.

[94-D2]

Lantley wrote:
I sort of had the same issue. Basically a poor installation. I replaced the tank myself with a brand new tank. I did not trust that a repair would be permanent or foolproof vs. replacement.

I found the model but a new one does not come with the inlet, drain, over flows and monitors in.

Did your replacement come prepared or did you have to have them custom installed.

[Lantley]

I sort of had the same issue. Basically a poor installation. I replaced the tank myself with a brand new tank. I did not trust that a repair would be permanent or foolproof vs. replacement.

[94-D2]

blueglide wrote:
I bought this plastic welder kit a couple years ago and keep it in my rig full time. https://www.polyvance.com/Airless-Welders-1/5700HT/I needed it when I damaged my fresh water tank cresting an unusually steep short slope. It works great and you can also usually find people doing plastic welding/repair in any good size city. The spin weld fittings on your tank can probably be repaired easily since tank is out.

Thank you. I did a torch weld and got about 98%. Still leaked about an inch or two over night. I ordered the weld kit with the iron so should be able to Do it right. I’m not in a big city area so trying myself. Otherwise, Sacramento is just over an hour away. If someone had a shop suggestion for that Sacramento area that would be awesome!

[blueglide]

I bought this plastic welder kit a couple years ago and keep it in my rig full time. https://www.polyvance.com/Airless-Welders-1/5700HT/I needed it when I damaged my fresh water tank cresting an unusually steep short slope. It works great and you can also usually find people doing plastic welding/repair in any good size city. The spin weld fittings on your tank can probably be repaired easily since tank is out.

[94-D2]

The tank is out. The weld at the fitting flange is thin and weak. I found that there is no such thing as a direct replacement tank. They use whatever tank the manufacturer sources and the fittings are custom installed wherever they need them, either on site or spec’ed out. Either way, even if I replaced the tank, I would have to also custom install the fittings and tank monitor, so that renders replacement moot. So, working on that now and cleaning up all the wiring and hoses.