replacement gas pilot line and thermocouple

You might even be able to find that 1/8” pilot gas line on an old residential water heater or luckily you can find that kit that is shown. LP pilot orifices are usually .013 inch.Plain Jane thermal couples are normally 30 mV open circuit. The 250, 500 and 750s were called pilot generators and they would operate the millivolt gas valves directly, for the very old buildings that didn’t have electricity yet. I used to work on a lot of that old stuff.
All the 30 mV thermal couples I saw had the same electrical end and if you look closely it’s a very odd double thread. Craig

Okay, a small update. With luck I managed to find another furnace, the exact same model as my current one, with an intact pilot assembly and thermocouple. yahoo!
I'm now in the process of combining parts from this new used furnace into my old/non functional one. But I'm stumped getting connections at the gas valve loosened. Any tips? the connections look like they have some kind of goop holding them together, which is now quite hard. I have used a bit of Kroil on the thread to no avail (if you're familiar with Kroil, if it doesn't do the trick, I don't know what will). I'm pretty loathe to just reef on the small connector nuts for obvious reasons. Is this a place where a bitnof heat might be used, once I make sure all residual propane is gone? I'll include a photo of the sealing material if I can figure out how to post an image.

This is the "new" old furnace. You can see the dried sealant where the main propane line fitting is screwed into the gas valve. My other, current/not working furnace doesn't have this.

The brass fitting at the 1/8" aluminum pilot line is the one I'd need to loosen to be able to move the whole pilot assembly to the other furnace.

I'd also like to remove the pilot line from the pilot assembly plate so I can clean up the orifice, etc., and if nothing else have it in a better state so that I could easily remove and clean while on the road in the future. But, that brass nut and threads look like this... any thoughts about loosening it other than waiting for the Kroil to take more time? it's a tiny 8mm bolt, and this pilot line and assembly are basically Unobtainium, so I need to be pretty careful not to bung anything up...

That yellow goop you see on the gas line is a gas line thread sealant like a product called Rector seal. Becomes flexible when warmed up. I would try a six point flare nut wrench and a hammer to strike the end of the wrench on both nuts that you are trying to loosen. A little bit of heat would probably help loosen the larger gas line nut but I wouldn't overdo it.

ernie1 wrote:
That yellow goop you see on the gas line is a gas line thread sealant like a product called Rector seal. Becomes flexible when warmed up. I would try a six point flare nut wrench and a hammer to strike the end of the wrench on both nuts that you are trying to loosen. A little bit of heat would probably help loosen the larger gas line nut but I wouldn't overdo it.

Thanks Ernie, I'll try that if I end up needing to remove that fitting.

I did manage to get the pilot assembly out to move it over to my existing furnace.
But... the aluminum pilot line sheared off right where it goes into the coupling nut at the gas valve end. I have an extra pilot line with fittings that I managed to find, but I have an issue with the end where it goes into the pilot.
Can anyone tell me what the little ferrule compression ring is called on the end of the gas line? it appears to be only one sided. I need to cut the new line short, and get another one of these little compression rings, and set it on there so the same amount of line extends past it to match what is on the stock assembly. But I don't know what that little compression ring is called to search for one online. It also appears I need one with a different taper. Photo is the new pilot line on the left, end of the old pilot line on the right.

Grrrr, this stuff all seems almost standardized, but not quite....

Edit: or, is the brass compression ferrule on the old pilot line on the right, just a regular olive type compression ring and do they just compress down to look one sided after tightening them down? See second pic for what I mean.

Two different kinds of ferrules. Also, I believe the one on the left is aluminum and the "ferrule" is actually formed into the aluminum tube with a tool.

larry cad wrote:
Two different kinds of ferrules. Also, I believe the one on the left is aluminum and the "ferrule" is actually formed into the aluminum tube with a tool.

yeah they definitely are. Any idea where I could source a ferrule like the one on the right?

Kevinski wrote:

larry cad wrote:
Two different kinds of ferrules. Also, I believe the one on the left is aluminum and the "ferrule" is actually formed into the aluminum tube with a tool.

yeah they definitely are. Any idea where I could source a ferrule like the one on the right?

Typically the ferrule comes with the fitting and is the ferrule that is required for that fitting. I think the ones shown are suitable for propane, but defer to others to confirm.

I also agree with others that you should heat the hardened goop to free up the fittings.