1913 Possible Broken Pipe?

[vocoder]

Was out dry camping this weekend and had a horrible odor in the bathroom. Not a typical 'black tank' smell, but equally unpleasant.

It hit me HARD when I opened the cabinet door under the sink. I noticed that the low point drains have a sealing compound around them at the floor, but the sink drain doesn't. All drain pipe fittings are secure from the sink to the floor, so I'm wondering if there's a crack between the floor and the top of the tank that is letting the odor seep up around the drain hole?

Has anyone had something like this happen to them? How'd you fix it?

[Rivrock]

Check the black tank. My black tank on my 1913 was falling off the trailer when I got to camp on my first outing. The pipe from the toilet to the black tank had a 1" gap! Took it in and the bar holding the tank was repaired.

[fonzie]

check your air admittance valve underneath sink if closing properly (if you have one there) as smell from grey tank will flow back....

[vocoder]

Sorry it's taken a while to post my results - the air check was exactly the problem. Replaced it and spent a few great days at a private lake without any bad odors. Thanks Fonzie.