Sounds like a missing "O" ring. There should be an o-ring seated in the female connector (The part that is not holding on) if it's missing, or if it is too thin, you won't have friction to hold the hooks on the pins.
Nothin adds excitment like something that is none of your business
Kenwood TS-2000 housed in a 2005 Damon Intruder 377
Another trick is if you have any doubts about how sealed the couplings are, run some gray water out first. If that leaks it's much less of a mess. If you see no leaks, shut off the gray, proceed with black until done. You can then resume dumping gray to flush your dookie tube.
Dakzuki wrote: Another trick is if you have any doubts about how sealed the couplings are, run some gray water out first. If that leaks it's much less of a mess. If you see no leaks, shut off the gray, proceed with black until done. You can then resume dumping gray to flush your dookie tube.
Nice idea. I will be making the first trip in a new TT with new hoses soon. I think I'll do this first time out just to check everything out.