After some struggle dragging out 350 foot of hoses, I did manage to top the stock tanks before dark yesterday afternoon.
Along about midday, a contractor friend came over to take a looksee. This guy has installed a number of these over the years, and had a hunch what the issue right away. So, a few trips to the house for tools later, the head part was off the hydrant.
Once it was exposed it was easy to see what the problem is. There is a small crack on the head itself (which is generally no big deal, just a hairline on the cast iron) that leaked, which has created a lot of rust between the draw pipe, and the exterior pipe. Now these two pipes are a very tight dry fit anyway-but it's totally gummed completely around the diameter. We sprayed some WD 40 on it, and then attempted to rotate the head after reassembly-which would break the works loose, in theory. Of course it won't move at all.
The contractor is pretty sure that the O rings are shot on the bottom of the thing, at the valve. Since we need to pull it anyway to clean off the rust and crud, these should be replaced. Of course, just getting it loose is the trouble....in speaking with my hub last night, he said he had some penetrating oil that I should apply a few times today. It's his opinion that the oil will do the trick...so once it gets to be light out, I will be applying that.
On Monday my friend will be back to see what he can get repaired. If we can't get it loose, then we will have to dig the blasted thing up. If I have to go that route, I am getting a different type altogether, one less complicated and easier to maintain if needed.
In the meantime, all the hoses are in the garage in a huge tangled pile, and the horses DO have water.....