I am slowly picking off the winterizing steps for my pool. I have had a cover over it for a week and drained the equipment, now I am blowing out the lines. When I set up the plumbing, I brought the skimmer and bottom drain lines into a 3-way valve and then through a check valve into the pump. I blew out the skimmers to the pump no problem, but to blow out the bottom drain I had to get creative. I was able to open the check valve with a wire and then hook up a line from my compressor to blow them out. I had air bubbling out almost instantly so everything looked great. I shut off the air and switched the 3-way valve to block the bottom drain and pulled off the fitting I use to hook up the compressor and I could hear the sound of air bubbling by the valve. The Jandy valve must not be able to stop air flow in the reverse direction. With how they are mad, it makes sense because with water trying to flow through it the correct way, the water pressure will help to seal the valve shut but in reverse, it isn't really built stout enough to seal.
I ended up capping the line where it connects to the pump and plugging the skimmers threaded plugs but I imagine it will leak enough somewhere to let the bottom drains fill again. Should I cut up the bottom drain line and install fittings to cap it more securely or is what I have done so far likely to work?