Very Small Propane Leak

[Tetonper]

I know there are other posts on propane leaks and how to find them but want to make sure it is understood how difficult this one has been and what we have done.  So camping one trip I thought I smelled propane a time or two.  Then the propane monitor went off on 2 different occasions when there was no wind outside.  I spent over 30 years in a gas plant making and loading propane.  Mercaptan/sulfur actually causes some loss of smell over long term.  So when I do smell I am sure it is there.  No appliances or heater, other than the fridge were operating at the time.  When I close the valves on the propane tanks it loses pressure in about 3 to 5 hours.  It used to stay up for a couple days when we bought the camper.   I was a maintenance man, instrument tech and operator as well so I have chased many leaks and am well versed in methods.  After extensive search, soaping plugging all the lines going to heater, hot water, & fridge, buying a new regulator and such I asked for some help as it still drops to no pressure.   So I assume it is in the feeder line somewhere but it is very difficult to replace on this camper.  A friend in the industry sent his FLIR GasViewer camera with a tech over.  He could not see any leaks and literally spent an hour looking on a 27' camper with lines connected and plugged.  I will replace the mainline if I have to, but I don't want to do that if I don't have to.  Any thoughts or ideas??  This is not out of my line of knowledge or expertise.  I have found literally thousands of gas leaks over the years using everything from hearing, smell, seeing vapors and technology.  Pretty sure no tech in an RV shop has the tools we do so looking for someone who may have found something unique or just has an idea to try.  I will take any and all.  Will only say I tried it if we have.   Yep it is driving me nutso and I am not into laying under the camper for 3 or 4 days changing a line out if I don't have to.  I am going back now to plug all connections going up in the camper one at a time and retest but all experiences are worth hearing to me!!

[opnspaces]

Over the years I've heard about many oven pilots leaking so definitely check there.
I wonder if it's something that only happens when a load shuts off. Like the refrigerator turns off and the gas pressure briefly spikes.
If it has black pipe under the trailer I would think that was the last place to leak.

[naturist]

All I can offer is my sympathy and best wishes for finding that leak. 

[Tetonper]

Thanks, it is kicking my butt.  Can't think of too many leaks over all these years I didn't find or get others to help nail down.  Appreciate the good wishes.

[joebedford]

My leak was the fridge feed. It's in my slide and the line flexes every time the slide goes in or out.

[Tetonper]

Thanks.  Fortunately not in my slide but I will see if I can get up above and check it out higher in that line.  Propane is heavier than air and could easily drop down to the floor and trip the monitor.