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Topic: Leak at pump supply fitting on fresh water tank (Read 674 times) previous topic - next topic

Leak at pump supply fitting on fresh water tank

I have a small drip from the fitting on the bottom passenger side of the fresh water tank where the water pump supply hose connects to the tank.

Last fall, I had to remove the brass nipple that threads into the fitting on the bottom passenger side of the fresh water tank to re-plumb to allow the water supply pump to circulate the potable anti-freeze throughout the coach water piping for last winter.  When I threaded the brass nipple into the fitting on the water tank, it never felt tight.

When I put bleach water in the tank a few days ago to flush and sanitize the water system, I noticed I had a slight drip from this fitting.  I emptied the tank today and removed the brass nipple and then reinstalled it and reconnected everything.  Again, it didn't feel like the brass nipple threaded tightly into the fitting on the tank.  After refilling the fresh water tank, I noticed I still have the slight drip from this fitting.

I am thinking the threads inside the fitting on the tank have been damaged so the brass nipple does not thread in tightly.  But I am guessing.

Will using JB Weld on the threads in the fitting on the tank and the threads on the brass nipple seal the nipple into the fitting on the tank to stop the slight leak?

Or is there a better way to resolve the issue?

Thank you very much.

Morris and Janice
1997 U270 36'

Re: Leak at pump supply fitting on fresh water tank

Reply #1 –
Morris,

You might consider wrapping the threads with teflon tape or perhaps using plumber's dope on the threads.
Rudy Legett
2003 U320 4010 ISM 450 hp
2001 U320 4220 ISM 450 hp
1995 U320 M11 400 hp
1990 Granvilla 300 hp 3208T
Aqua Hot Service Houston and Southeast Texas

Re: Leak at pump supply fitting on fresh water tank

Reply #2 –
Morris,
I agree with Rudy.  I would never use J B Weld on a fitting that you may need to remove in the future.  I installed a bypass valve at the water pump inlet so this makes it easier to winterize the coach.
Peter & Beth Martin
No Forrest? What have you done?
MC# 15890 until Dec 2016; FMCA #F329677
Cincinnati, OH

Re: Leak at pump supply fitting on fresh water tank

Reply #3 –
Quote from: Rudy –
Morris,

You might consider wrapping the threads with teflon tape or perhaps using plumber's dope on the threads. 

I used teflon tape last fall when I removed the brass nipple to replumb to circulate the antifreeze.  I have not tried the pipe dope.  Is it the regular pipe dope used on steel pipe fittings?

Morris and Janice
1997 U270 36'

Re: Leak at pump supply fitting on fresh water tank

Reply #4 –
Morris, I don't think JB Weld is approved for potable water. I would use a potable water approved caulk or sealant that would not make a permanent connection.
The selected media item is not currently available.Kent Speers
Locust Grove, OK
1993 U300 SSE 40' (Restored at FOT 2009) Build 4323
720 watts Solar
6V92TA DDEC Silver Engine
2014 Subaru Outback

Re: Leak at pump supply fitting on fresh water tank

Reply #5 –
I think you made a mistake by removing the water tank side of the supply hose. A better choice would have been to remove the water pump side of the supply hose as often an old fitting will leak when disturbed.

I also think that metal connectors should not be used in plastic tanks. There are plastic connectors that are better suited as metal may damage plastic threaded hole in tank.

When the water pump end of the supply hose is removed, a ball valve should be installed to allow future changing of water pump without having to empty the water tank

You may find a way to make a leak tight repair at water tank by using a plastic fitting to which a hose can be connected. Using multiple layers of thick yellow or pink 'teflon' PTFE tape on the threads of this new plastic fitting may allow a tight connection. Be careful to not cross thread the fitting.

Re: Leak at pump supply fitting on fresh water tank

Reply #6 –
Quote from: Kent Speers –
Morris, I don't think JB Weld is approved for potable water. I would use a potable water approved caulk or sealant that would not make a permanent connection. 

Does anyone know what adhesive they use to install the fittings in the tank wall when they manufacture the tanks?  I am sure it has to be approved for potable water.
Morris and Janice
1997 U270 36'

Re: Leak at pump supply fitting on fresh water tank

Reply #7 –
Morris, just google "potable water epoxy". There are dozens of them listed.
The selected media item is not currently available.Kent Speers
Locust Grove, OK
1993 U300 SSE 40' (Restored at FOT 2009) Build 4323
720 watts Solar
6V92TA DDEC Silver Engine
2014 Subaru Outback
 

Re: Leak at pump supply fitting on fresh water tank

Reply #8 –
A propane company locally told me about a pipe dope product called Rector Seal 5.  It can be used on potable water, LP gas, natural gas, compressed air and other liquids/gases.  I got a bottle this afternoon and drained the fresh water tank this evening.

I plan to remove the nipple and use the pipe dope on the threads and reinstall it. 

Hopefully this will resolve the problem.  I will let you know.
Morris and Janice
1997 U270 36'