I would like to add this tank (WTAN022) under my Offroad Teardrop trailer (over the frame instead of over the trans) so it would be mounted upside down. Does this accept trailer fill lines? Kyle Relleen 03 May 2020 15:06 Updated Follow This tank was designed to be gravity fed from top to bottom and it has a 1/2 inch NPT port. We do not recommend mounting the take upside down. Front Runner team. This question is about: Footwell Water Tank - by Front Runner (WTAN022) Comments 0 comments Article is closed for comments.