Belly Mystery

[packdad52]

I thought I was taking out a drain plug on the bottom of my 1976 Caravanner. After soaking it with WD40, I tried to remove the "plug". Turned out the plug was not a plug but a nut that held up a steel plate on the bottom of my fresh water tank. The nut broke off the bolt and I haven't a clue as to what to do next. Is this an aftermaket rig or an Airstream option? I have never seen a belly extension like this on any other Airstream. I still haven't found the drain plug if there is one. Any information would be very helpful.

[Melody Ranch]

Could it be a load distributing plate used to hold the odd tank up? It is steel for some reason.

[steelbird312]

Packdad,
This is nothing more than a shot in the dark....from your pic, it appears it may be an access door for some reason. There is a piece of hose in there as well as some wiring as well? Is the pic supposed to be looking upward? It appears as if you soaked the broken stud with kroil for a couple of days, you possibly could grab it with a pair of vice grips and remove it. Just do not hurry the process; let the rust remover work and the frustration level will go WAAAY down. Then replace broken with new, things would be as they were and WE could be left wondering, just what is in that hole.................

[Aerowood]

Wow, It looks like you have some serious corrosion going on on the belly pan

[packdad52]

Does anyone with a mid '70's Caravanner or Tradewind have a similar fresh water tank? I do think this is some kind of support. I was hoping someone with a similar tank or knowledge of this one would reply. The tank cover appears to be galvanized and it is held on with hex head fasteners.

[ticki2]

Packdad52

I have the same unit , '76 Caravanner , with the same set up . The steel plate is indeed an access cover AND a support for the center of the water tank . The bolt on mine is 1/2" coarse thread . The hose goes from the tank to the water pump . Mine did not have a manual drain for the water tank . I cut the hose and installed a T with a drain valve . As was stated earlier , soak it-soak it-soak it , several days at least . I would not try heat as the plastic tank is too close . If the soaking doesn't work you will have to drill it out and re-tap it . Be patient , if you are not comfortable doing it , any good mechanic can drill and tap it . When you have it repaired replace the bolt with stainless steel . Good luck

[wlj1943]

Everyone is right on line with my experience. I find applying Kroil at least daily (more often when it is hotter) and tapping the broken fastener while trying to carefully twist with the vicegrips (both ways) is a help when no heat can be used, as is the case here. Every 10 degrees or so of temperature drop below 20C will make Kroil work about 1/2 as fast, so it works faster in a heated shop in winter; but Packdad may have any winter this year like many others. I have never had Kroil fail given enough time and consistent applications, even on salt water rusted steel parts.
wlj1943