Tried to reply to you post, but for some reason it logs me out every time. The last Argosy I had it was about 12" behind the road side back tire. The only other location I've seen is outside the back bumper on road side, if it has a whole and not fitting, it's been modified. I had an Airstream that someone didn't know about a check valve and cut it off an put a cap on it and used only fill tank and pump. You never know with some owners.
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