Originally Posted by Seawway
Thanks everyone for all of your ideas. I finally got out to work on it this weekend. And once I put the water pump into action I discovered why it will not drain. There were four holes in the water lines from inappropriate winterization. I can’t tell if the freshwater tank has a hole in it but it seems like it does as well. But for sure it looks like PEX here I come. Thanks again for everyone’s ideas. I’m sure I’ll have to start a new thread for a plumbing problem that I will encounter installing the PEX. When re-plumbing I intend to install winterization drains for the water system to prevent this type of damage in the future.
Please see my last post about the water tank drain.
Sorry for your discovery of leaks in the the plumbing! To be expected with an older trailer IMO, unfortunately.
As you re-plumb, it still remains important that you find the water tank drain valve and consider replacing it, along with all your other new work and low-point drains, just to be clear. You should be able to see where this tank drain exits the belly pan, more or less under the fill spout for the tank.
Are you going to have to remove the belly pan [at least in sections] to re-plumb?
Your Airstream probably had sufficient drain valves, if they had been used correctly, to avoid freeze damage to the trailer IMO. After draining all the lines, a final blow-out with compressed air should be the only insurance you need, not antifreeze. The older Airstreams had much simpler plumbing systems, and AS was pretty good about making sure that their winterizing process worked well. We had a 1985 25' Sovereign
which was simple to winterize.
See p. 20 [PDF p. 24] in the manual linked in the last post, where there are very detailed and specific winterizing instructions. Even if this is not your exact manual, the same steps would apply to yours IMO.