At the end of the season prior to putting the camper away for winter I suddenly got a leak coming out of the rear of the TC. It was too cold to do anything about it so I drained everything and waited ...
Is it black ABS pipe? Those use thinner-based glues, meaning the glue is actually melting original material (just like steel welding). Meaning you can file V-grove in the crack and with few application with dry time between- rebuild the fitting.