Need Recommendations for Fixing Leak at Propane Gage Fitting

[Seward G]

I have a leak at the threads of the gage on the side of the propane tank. The RV is a 2013 Monaco Monarch. The on-board tank is 16 gallons. The photo shows soap bubbles at the threads of the gage.  Please provide suggestions for a service center where I can get this leak repaired.  The tank is 1/4 full now.  

Correct me if I am wrong - I believe the gage senses the level of the liquid propane in the tank with a float. The float and gage then would have an "up" position to work. The leak cannot be sealed by turning the gage tighter by a quarter revolution. The permanent fix may be to evacuate the tank, remove the gage, apply pipe dope, and reinstall; an expensive proposition.

Suggestions?

[tmw188]

You might ask a large propane supplier or facility if they can evacuate it? Some I believe would fix it live.  I have my own ideas on how I would do it if it were mine, but would rather not bring it up here. It is very low pressure. I have a T tapped into the pipe on the patio side with a valve and disconnect that I use for a griddle or fire pit that would come in handy for something like this. 

Edited December 13, 2024 by tmw188

[Jetjockey]

If you can take wire off sender,try to take it a full turn tighter. Probably what the shop would try first.

[Scotty Hutto]

3 hours ago, Jetjockey said:

If you can take wire off sender,try to take it a full turn tighter. Probably what the shop would try first.

The gauge actually clips onto the sender and reads the float magnetically.  The gauge and wire just pops off.  Be careful not to break the plastic legs that hold the gauge to the sender.

I don't see any way to do it safely without evacuating the tank. I second the idea of talking to a propane dealer that might evacuate, repair, and refill the tank.  I suspect you are right... evacuate, unscrew the float without completely removing, clean the threads, yellow (gas) pipe dope or yellow (gas) teflon pipe tape, reinstall, leak test...

You might also want to reach out to the tank manufacturer (Manchester Tank Co, https://mantank.com/) to see if they have any advice.

[Benjamin]

If the gauge rotates or clips on, I'm not so sure the screwed in part has to be in the same orientation.  If you want to attempt it, give it half a turn and see if the gauge reads correct. 

 

[Scotty Hutto]

4 hours ago, Benjamin said:

If the gauge rotates or clips on, I'm not so sure the screwed in part has to be in the same orientation.  If you want to attempt it, give it half a turn and see if the gauge reads correct.

To my recollection, it doesn't have to be the same rotation.  I had this exact setup on my 2002 Holiday Rambler Vacationer.

[cbr046]

Looking at how floats are made I'd say orientation is critical . . . . but call and ask Manchester Tank.

- bob

 

[Seward G]

Thanks everyone for the suggestions. We will be on the road in a couple days.  I don't want a botched fix to delay our leaving, so I will work on it when we get to Georgetown, Texas in a couple weeks.  I don't smell propane, and the gage does not show significant propane loss, so I think I'm ok for the next couple weeks.

I called local propane dealers and RV shops  but did not find anyone to work on the leak. I also called a propane supplier in Georgetown that a friend had used for a similar problem. They weren't helpful, and said don't come here with that problem. 

Once in Georgetown, I plan on using up the tank propane. I have the "add-a-tank" kit installed so when the on-board tank is empty I can still use a 20 pound bottle of propane for the stove. I plan to remove the magnetic sensor for remotely reading the gauge, unscrewing the float assembly most of the way out, clean the male threads, apply pipe dope, and screw back in the same number of turns as on the way out.  I am thinking I will be able to use the 20# bottle gas to find out if there is no longer a leak. The 20# bottle pressure will be about 150 psi.

If that doesn't work, then unscrew the gauge all the way, remove the float assembly, clean all threads, and reinstall.  Test again.

I believe gauge orientation is critical. 

Jerry Gilbert

[Jetjockey]

Your leak is very small. I think many would find similar small leaks if they investigated. Some leaks such as yours cam occur in cold conditions and not in warm . Different expansion rates between dissimilar metals. We have dealt with lpg in many tanks for years. Gauges on them are notorious for small leaks. I have had them apart and everyone had a float that had to be indexed correctly. The gauge is likely brass tapered threads that tighten up as you turn it in.  If it were mine I would try to give it a turn. As you start turning it will become evident whether it can go a whole turn. If not go to a supplier or possibly hvac shop. I kind of doubt a supplier can pump the liquid as those tanks are usually vapor withdrawal only.  Likely that leak has existed since manufacture.

[Steve P]

On 12/27/2024 at 8:53 AM, Jetjockey said:

Your leak is very small. I think many would find similar small leaks if they investigated. Some leaks such as yours cam occur in cold conditions and not in warm . Different expansion rates between dissimilar metals. We have dealt with lpg in many tanks for years. Gauges on them are notorious for small leaks. I have had them apart and everyone had a float that had to be indexed correctly. The gauge is likely brass tapered threads that tighten up as you turn it in.  If it were mine I would try to give it a turn. As you start turning it will become evident whether it can go a whole turn. If not go to a supplier or possibly hvac shop. I kind of doubt a supplier can pump the liquid as those tanks are usually vapor withdrawal only.  Likely that leak has existed since manufacture.

Seriously?  I just added an Extend-a-Stay to my propane to connect a 20lb auxiliary tank.  The POL connector (with the o-ring) is leaking about that much.  I took it off and tried yellow tape.  Made no difference.  Took it off again and removed the yellow tape.  Still bubbling slowly no matter how much I tighten the fitting.  Should I be worried?

Edited Wednesday at 04:34 AM by Steve P

[Rocketman3]

On POL fittings the O- rings go out (that is actually what makes the seal). Just get the O-ring replaced and it should fix the leak.

My main valve was not shutting off - open or closed propane flowed at the same rate. Finally we ran our 45 gallon tank out of propane completely! (Double verify that!) I got a replacement valve. Pulled the tank halfway out of the rig - had to use cheater bars to break it loose - 3 to 4 feet total length (one to hold the tank and one to twist the valve). Then replaced the valve.  Wasn’t a very difficult job.

Good Luck!

 

[Jetjockey]

 . The  o ring pol fittings did not always exist. Used to be just brass to brass seat. I think the came when the tanks had an excess flow valve put in. Probably had less,leaks when the seat was brass  to brass. Lots of propane used on the farm with lots of various sized bottle and tanks. One thing  to remember always open valves completely . There is a seat at the top and at the bottom of the valve stem.