Tumbleweed36

Quite honestly, any quick fix is a real gamble. I predict with the temporary fix you will be right back where you are now in just a few weeks. The wonderful push joints most likely won't work here because of the limited space you have and in addition, having to go to the elbow to attach the push joint.

I am with Carsey on this one, get the solder gun out and take it off and redo it. Pex is not an option (although very easy) because you can't get the crimp tool down in that area.

If this were mine, I would put a vice grip on the 90 degree joint that is leading, take a torch (with a very limited spread flame) and heat that 90 degree joint and start moving it slightly side to side while it is heated, then pull at the same time and slip it out when the solder is melted. Then use some emery cloth to resand (put it underneath and pull it back and forth) the receiving pipe and clean that joint and make sure it is dry. Put some flux on there, reheat the 90 degree joint with solder at the joint area and it should go on there. I doubt even if close if you will dislodge the other joint, but if you do, it will reseal when cooled. BTW, if the pipe comes up through the floor, you might be wise to put the pipe that comes up through on the elbow before you put it back.

Another thought, if the pressure is out of there, you are still going to have some water moisture in that pipe (since it is down low) which can keep them from sealing if soldered. If that is the case, let it drain all the water out and when you get most of it done, put a bread plug in the pipe before the joint area and that will keep it dry until you get it soldered. When you turn on the line, the bread will disintegrate and flush out of the line with the water.

Been there and done that one a few times. My son called me one night about 8:00 p.m. and had a bad leak that was similar in a setting that was just about like yours.

He called a plumber who told him it was impossible to do unless he took out part of the floor. Well, the estimate was $900 for tearing out part of the floor, repairing the joint and repairing the floor he had to take out. (he didn't have that kind of money since he was just starting his family) My son lived about 100 miles away and this was in early evening. Being a good dad, I jumped in my car with all my tools and away we went. When we got there, repaired it similar to what I explained above, took about thirty minutes...soldered it up, drove back home and the cost to him was nothing. Darn thing never leaked again.