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Topic: Freshwater Tank Leak (Read 760 times) previous topic - next topic

Freshwater Tank Leak

After our last trip, I noticed some water in the wet bay. Traced it down to the 1/2" female connection on the bottom of the tank that connects to the water pump. It's a glued in fitting at the very bottom, appears to have a split from over tightening the male adapter and the Teflon tape used for sealing the fitting probably contributed to this. This coupled with thousands of miles traveling on our pot-hole filled interstates.

Any suggestions on a fix? Short of pulling the tank for repair or replacement. JB plastic weld? Flexseal caulk?
Can the fitting be removed and a new one installed?
Justin & Cathy Byrd
1995 U280 "Old Faithful"
36' Build #4673
C8.3 Cummins
Allison MD3060R 6 speed - retarder
Powertech 10KW  4cyl Kubota

Re: Freshwater Tank Leak

Reply #1 –
Can't help with your specific question, but be sure to "mop up" any water that spills in there or it will get into the rear bulkhead structure and cause damage.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Freshwater Tank Leak

Reply #2 –
Any chance for a picture.
96 U270 BUILD 4810
85 380SL
Drummonds TN.

Re: Freshwater Tank Leak

Reply #3 –
I'll get a few photos later this morning.

Removing and replacing a spin weld fitting doesn't appear to be a option without removing the tank.
Justin & Cathy Byrd
1995 U280 "Old Faithful"
36' Build #4673
C8.3 Cummins
Allison MD3060R 6 speed - retarder
Powertech 10KW  4cyl Kubota

Re: Freshwater Tank Leak

Reply #4 –
Had the same fitting crack on my 96 about 10yrs. ago while in Quartzsite/Yuma for the Winter. I pushed the tank out from passenger side to drivers side since the hot water tank is installed on that side in front of the tank. Using a length of 2×4 and block against the tank I  pushed the tank out far enough to grab hold and pull out from drivers side. Luckily I found a RV repair shop locally that was able to spin weld a new fitting on for 20 bucks. Hardest thing was reconnecting overfill hose, had to add a length of hose as to have enough room between hot water and fresh tank to make connection.
Doug W.
96 36' U270 CSGI #4946
04 Toyota Tacoma 4x4
PNW

Re: Freshwater Tank Leak

Reply #5 –
Three armchair solutions (that don't require tank R&I) come to mind:

1.  If your tank is like ours, you have two water pipes exiting the tank in that area - one to supply the pump, and the other is a drain line.  You could seal off the cracked female fitting with some kind of expanding rubber plug combined with a waterproof sealing cement.  Then install a "T" fitting in the adjacent drain pipe and run a new supply line off the "T" to the water pump.

2.  If the crack in the female fitting is only in the threaded area, and doesn't extend up into the welded base, then you could try screwing in a permanent male/female threaded adapter using some kind of waterproof sealing cement.  If there is room on the neck of the (cracked) female connection you could also install a narrow metal hose clamp that (when tightened) would close up the crack in the female fitting and tighten up the threads.  See photo of adapter below.

3.  If the crack in the female fitting goes past the threaded area and extends into the welded base, then you could remove the fitting using a 1.25" hole saw.  Install a 1/2" UNISEAL in the 1.25" hole, then push a 1/2" PVC or PEX pipe into the UNISEAL and go from there.  I used a UNISEAL to make a "quick fill" adapter on our water tank.  It works great, and has never leaked, BUT it is normally above the top of the water level, and is only exposed to water sloshing around when the tank is full.  Link below (Reply #29):

What did you do to your coach today VII

1/2'' White Original UNISEAL - aussieglobe.com

1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Freshwater Tank Leak

Reply #6 –
If Crack is not into the base, I like the hose clamp idea from above post.

2014 ih45  (4th Foretravel owned)
 1997 36' U295 Sold in 2020, owned for 19 years
  U240 36' Sold to insurance company after melting in garage fire
    33' Foretravel on Dodge Chassis  Sold very long time ago

Re: Freshwater Tank Leak

Reply #7 –
I'm with the hose clamp idea also.
Peter and Frieda Morin
1999 36ft. U320 Foretravel
Build # 5436
1998 Suzuki Sidekick Sport

Re: Freshwater Tank Leak

Reply #8 –
Quote from: oldguy –
I'm with the hose clamp idea also.

I did the hose clamp fix while I spent a week or so in Quartzsite, for me it was not 100% leak free fix.

Mine had a small plastic filter about
 2 inches long that slipped into the fitting.
Doug W.
96 36' U270 CSGI #4946
04 Toyota Tacoma 4x4
PNW

Re: Freshwater Tank Leak

Reply #9 –
Quote from: Doug W. –
Had the same fitting crack on my 96 about 10yrs. ago while in Quartzsite/Yuma for the Winter. I pushed the tank out from passenger side to drivers side since the hot water tank is installed on that side in front of the tank. Using a length of 2×4 and block against the tank I  pushed the tank out far enough to grab hold and pull out from drivers side. Luckily I found a RV repair shop locally that was able to spin weld a new fitting on for 20 bucks. Hardest thing was reconnecting overfill hose, had to add a length of hose as to have enough room between hot water and fresh tank to make connection.

I may have to remove the tank, it appears that the door and trim will need to be removed before the tank will slide out. I'll try to repair the fitting first with either a JB weld product or another product called MMA 500 for polymer plastics.
Justin & Cathy Byrd
1995 U280 "Old Faithful"
36' Build #4673
C8.3 Cummins
Allison MD3060R 6 speed - retarder
Powertech 10KW  4cyl Kubota

Re: Freshwater Tank Leak

Reply #10 –
Quote from: Doug W. –
I did the hose clamp fix while I spent a week or so in Quartzsite, for me it was not 100% leak free fix.

Mine had a small plastic filter about
 2 inches long that slipped into the fitting.

I have tried the hose clamp trick with a GOOP sealant, It didn't work.
Justin & Cathy Byrd
1995 U280 "Old Faithful"
36' Build #4673
C8.3 Cummins
Allison MD3060R 6 speed - retarder
Powertech 10KW  4cyl Kubota

Re: Freshwater Tank Leak

Reply #11 –
I'm renewing this old thread, similar problem, a new leak seems to have appeared. Much smaller leak but enough that I have to figure it out. The old leak at the female fitting outlet to the pump was repaired with Flex Glue and Flex Seal. It appears to be holding up and no sign of leaking from there. Moisture / water appears to be coming from the bottom of the tank or from behind the aluminum bracket that keeps the tank from moving to the passenger side of the bay. Not sure, so my plan is to remove the tank soon to find out.

I leaning strongly towards replacing the tank with a new one. It's a pain to remove I'm sure so might as well install a new one and be done with it.  After 30 years of bouncing down our raggedy @$$ interstates, it's time to retire this one. Problem is........... finding a new one. Elkhart Plastics at one time stocked the exact tank (207 W) 102 gallon. According to their Rep. they no longer sell it to the general public and it's only available by special order of at least 10 units. Unless there are nine more members interested in a new tank?? I will need a "Plan B".

If anyone knows of another source of this tank, please let me know!
Justin & Cathy Byrd
1995 U280 "Old Faithful"
36' Build #4673
C8.3 Cummins
Allison MD3060R 6 speed - retarder
Powertech 10KW  4cyl Kubota

Re: Freshwater Tank Leak

Reply #12 –
Check with other tank manufacturers. I had one made for my '81 by a company that made one off tanks by measurement. I am not at home out on vacation. When I get home and if you are still looking I will dig up the receipt and post the manufacturer. It is in Southern Cal.
1999 40 ft. U-320 wtfe build 5563 Chuck & Lynda's "Rollin' Inn"  2030 watts solar
prev. mh's 71 GMC 5 yrs. 73 Pace Setter 1 yr. 78 Vogue 5 yrs 81 FTX 40ft all electric 18 yrs. 1996 Monaco Signature 3 yrs.
2014 Grand Cherokee Overland
Dream as if you will live forever. Live as if you will die today.  James Dean

Re: Freshwater Tank Leak

Reply #13 –
Get a hole saw big enough to cut the whole fitting out and use a Uniseal Pipe-to-tank seal then some reducing fittings to get back down to size.    I have one on my tank and it's actually fascinating how easy and well it works.  Once you use one, you'll question why the welded fittings even exist.
https://www.usplastic.com/catalog/item.aspx?itemid=89951&srsltid=AfmBOopkAhxFXWbGhewhL6uhD-S1eQzOHGCoTAEFRhg0MaGeFBS6qntl
Ted
2014 IH-45  #6585
Louisville, KY

Re: Freshwater Tank Leak

Reply #14 –
Quote from: Ted_L –
Get a hole saw big enough to cut the whole fitting out and use a Uniseal Pipe-to-tank seal then some reducing fittings to get back down to size.    I have one on my tank and it's actually fascinating how easy and well it works.  Once you use one, you'll question why the welded fittings even exist.
https://www.usplastic.com/catalog/item.aspx?itemid=89951&srsltid=AfmBOopkAhxFXWbGhewhL6uhD-S1eQzOHGCoTAEFRhg0MaGeFBS6qntl

It appears to be leaking from somewhere other than the fitting now.

Justin & Cathy Byrd
1995 U280 "Old Faithful"
36' Build #4673
C8.3 Cummins
Allison MD3060R 6 speed - retarder
Powertech 10KW  4cyl Kubota

Re: Freshwater Tank Leak

Reply #15 –
Try searching plastic tank fabrication and your city, will probably be a handful of companies listed. They have plastic welders, used one 30 years ago to weld damaged marina dock floats. They are still in use and it was a fairly cheap repair, did it while I waited. good luck!
David & Emma Roche
Dino (Golden Doodle)
1999 U270 WTFE 36' Build # 5534
Xtreme "Lights, Stripes & Roof"
Motorcade# 18321
Dayton, Ohio
Towd: Jeep Grand Cherokee
Two Townie Electra Bikes

Life is made to enjoy, the Foretravel helps!