looks like you didn't finish the post.
you need to post year/make/model of RV you're talking about.
i'm assuming you want to know how to fill the FW tank, so knowing what RV you have is important.
Dan-Retired California Firefighter/EMT
and Zoe the Wonder Dog(R.I.P.)
2016 PrimeTime TracerAIR 255, pushing a 2014 Ford F150 SCREW XTR 4x4 3.5 Ecoboost w/Max Tow Package