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Leaking fresh water tank

LITEPHIL
Explorer
Explorer
Has anyone replaced their under trailer frame mounted 40 gallon fresh water tank? I bought my 08 25 ft Salem used and first time I used it I noticed a drip near the drain plug but it stopped and didn't leak on my second trip. Now I filled it up and it's got a pretty good drip going, so I will have to fix it when I get back. But looking closely at the leak, it looks like it has been repaired and is leaking above the drain plug and not the plug its self. I suspect it had a low hanging drain valve that got ripped off and then was repaired and now there is just a plug there. I can tell the tank had been out before since there's a unpainted weld. Anyhow, has any one replaced their under belly tank ? and if so, where did you find one. It looks like a pretty straight forward job, with a small amount of welding on the cross support.
Thanks!
2022 Chevy Silverado RST Duramax NHT
1954 Chevy 3100 Carryall 4x4
2008 Salem T23FBL
04 FXDL Harley
19 REPLIES 19

ralph_day
Explorer
Explorer
Speaking of fw tanks...I was filling with water before setting up camp and couldn't get the water to go in as usual...it burped and splashed back like never before. You could feel air being forced out the inlet past the hose. Hmmm. Crawled under the coach and found the overflow tube, sure enough a mud dauber wasp had plugged it. An ignition key for the truck (old school) was the right size to dig the mud out. Filled fine after that. I guess that's another thing to check when readying the coach for travel.

As water goes in air is forced out the overflow tube, unless it's plugged.

JRscooby
Explorer II
Explorer II
I dropped the tank cut a hand-sized hole in the top so could use glue on the inside of crack. Then patched the hole on the top well enough that nothing could fall in.

opnspaces
Navigator
Navigator
LITEPHIL wrote:
Sorry for not getting back sooner but I wanted to make a trip and make sure my repair was sound. My spin weld guy flaked out on me so I contacted a RV dealer near by that was recommended and he welded it for me. $200! I wanted a new tank but I guess they repair them all the time as some had advised me here.Little pricey but what isn't these days?
Thank you for the help!


$200 is a bit steep. But if it continues to hold it will be money well spent.
.
2001 Suburban 4x4. 6.0L, 4.10 3/4 ton **** 2005 Jayco Jay Flight 27BH **** 1986 Coleman Columbia Popup

ktmrfs
Explorer
Explorer
LITEPHIL wrote:
Sorry for not getting back sooner but I wanted to make a trip and make sure my repair was sound. My spin weld guy flaked out on me so I contacted a RV dealer near by that was recommended and he welded it for me. $200! I wanted a new tank but I guess they repair them all the time as some had advised me here.Little pricey but what isn't these days?
Thank you for the help!


the vast majority of plastic fresh water tanks are a material that is easy and best fixed by spin welding. Holds up great. In fact in these tanks most of the fitting that aren't molded in are spin welded at the factory. Most repair shops that do spin weld repair have an assortment of spin weld patches on hand. Basically the patch or fitting is spun against the tank and friction melts the junction, stop, let it cool and it's welded together.

For black/grey tanks, most are ABS which again is easy to fix, but instead of spin welding, solvent welding is done. Basically either use ABS glue on small cracks or use abs sheet material to bridge the break and solvent weld.
2011 Keystone Outback 295RE
2004 14' bikehauler with full living quarters
2015.5 Denali 4x4 CC/SB Duramax/Allison
2004.5 Silverado 4x4 CC/SB Duramax/Allison passed on to our Son!

LITEPHIL
Explorer
Explorer
Sorry for not getting back sooner but I wanted to make a trip and make sure my repair was sound. My spin weld guy flaked out on me so I contacted a RV dealer near by that was recommended and he welded it for me. $200! I wanted a new tank but I guess they repair them all the time as some had advised me here.Little pricey but what isn't these days?
Thank you for the help!
2022 Chevy Silverado RST Duramax NHT
1954 Chevy 3100 Carryall 4x4
2008 Salem T23FBL
04 FXDL Harley

Sjm9911
Explorer
Explorer
Yup , was going to mention that was an option. Good luck and tell us how it turns out.
2012 kz spree 220 ks
2020 Silverado 2500
Equalizer ( because i have it)
Formerly a pup owner.

LITEPHIL
Explorer
Explorer
Sorry to not get back about this sooner. I have a guy that has a place that will spin weld it for $150 if I take the tank out. I have another trip to the mountains next week, so I will pull the tank when I get back. Thank you all
2022 Chevy Silverado RST Duramax NHT
1954 Chevy 3100 Carryall 4x4
2008 Salem T23FBL
04 FXDL Harley

Baja_Man
Explorer
Explorer
I repaired my FW tank a few years ago on a TH I owned. Previous owner tried to use silicone to repair....wrong! Removing the silicone took longer than the repair! I used a plastic repair tool I purchased from Harbor Freight; it worked perfect! It's like soldering plastic. Just take your time, go slow, and it does work. Never had a leak again!

HF Plastic Welding Tool
2023 GMC, 3500HD, Crew Cab, 6.6L Gas/6 Speed Auto, 4X4, Standard Bed; SRW
2011 Outback 250RS - Anniversary Edition
Equal-i-zer 10K

Lantley
Nomad
Nomad
I was able to find the exact tank for my 2012 trailer. I purchased the unit new to my dismay the tank had already been repaired once by the factory or dealer prior to me aquiring the trailer.
I ordered the tank on line and swappede it out with the leaking tank.
I consider it a 7 job on a scale of 1-10.
No too difficult but you do have to remove underbelly and wrestle old tank out and new tank in but it's doable.
Contact manufacture or decent dealer to inquire about replacement tank.
19'Duramax w/hips,12'Open Range,Titan Disc Brake
BD3,RV safepower,22" Blackstone
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Correct Trax,Splendide

LITEPHIL
Explorer
Explorer
Taking off for the mountains for the week, so I investigate more when I get back but thank you
2022 Chevy Silverado RST Duramax NHT
1954 Chevy 3100 Carryall 4x4
2008 Salem T23FBL
04 FXDL Harley

mikey98e
Explorer
Explorer
You could try Trekwood RV parts. They carry RV parts. I found new cabinet doors for my unit that matched perfectly. I cut holes in the front of the bed frame so that we didn't have to lift the bed to store stuff and hung the cabinet doors to cover the holes.
-mike
Rose & Mike
2018 Tundra DC 5.7L 4x4 - 2013 Keystone Premier 19FBPR
Ruby the Red (Labradoodle)

Gdetrailer
Explorer III
Explorer III
LITEPHIL wrote:
I believe it's a standard size and hangs from the frame of the trailer. I want to get an exact replacement. Guess I should have made that clear that I want to replace it since it looks to have been repaired before. Don't want a custom tank just a replacement tank. My 2007 Forest River toy hauler had an identical set up and I remember the drain hung pretty low on that trailer.
My question is, has anyone replaced their underbelly tank and if so, where did you find it? If it's $1,000 I'll repair it but if it's $250-300 I'll buy a new one.
Thanks!


I will make extremely loud and clear.

There may absolutely be no EXACT replacements unless it comes from your EXACT YR AND MODEL or trailer.

Even though the tanks "look" like they are "standard" they are often not exactly the same. Often the dimensions will be different in one or more directions enough to require you to make all kinds of modifications to your frame and hanging system.

RV manufacturers tend to change designs like folks change their shorts, when they cease production of a model or model yr any excess parts which do not fit the new model or model yr are sold off to third party surplus dealers. Manufacturer may only hold on to some parts for a short time just to deal with possible warranty issues.

If you really want to go down that road, contact the customer service department directly of your brand of RV, maybe you will find a sympathetic ear that will be willing to leap off the edge for you and find your old tank.

But in the mean time, HERE is another place that will ORDER your tank by dimensions via third party manufacturers (notice RONCO is one of their manufacturers).

HERE is another supplier which may carry some "standard sizes" but the ones I looked at were all non flange rectangular tanks.

HERE is another RV tank place..

HERE is another RV tank place..

HERE is a web search using "rv replacement water tanks" as the search key words (search engines are your friend!).

But, I will say this, the "repair" that was done on your tank, may not have been "welded" or "welded" correctly. Lots of folks don't wish to spend money on a broken tank tend to take the cheapest route possible and attempt to use glues which often work for a short time and then fail.

midnightsadie
Explorer II
Explorer II
both you men are AZ guys ,you should talk.

Huntindog
Explorer
Explorer
I weld, both metal and plastic.

There are two problems with welding plastic.
1.matching the rod material to the item being welded on. There are a ton of different plastics out there. The best match will be a matching donor item. Anything else is problematic.
2.Age of the tank. Plastic degrades over time. At the 14-15 years of this tank, it is a tossup as to whether it will work or not.
If it were mine, I would give it a shot. If it was a job for a paying customer, I would pass.. Too much risk of it not working , and having to refund the money. I don't work for others for free.
Other than that it is still probably a somewhat difficult repair as it would likely be an overhead repair. Doable, but not easy, especially if the rod material is not perfect
Huntindog
100% boondocking
2021 Grand Design Momentum 398M
2 bathrooms, no waiting
104 gal grey, 104 black,158 fresh
FullBodyPaint, 3,8Kaxles, DiscBrakes
17.5LRH commercial tires
1860watts solar,800 AH Battleborn batterys
2020 Silverado HighCountry CC DA 4X4 DRW