Dirtytires
Explorer
Here is the Fill Port that i used. It cut into the side of the trailer and then I connected the large hose and a smaller vent hose. You can see in the picture where the vent is connected.
Here is the link.
http://cgi.ebay.com/ebaymotors/Grav..._Camper_Parts_Accessories&hash=item43a485c4af
The bottom 2 ports were used for the pump supply and the other for the tank drain out.
View attachment 71692
I have the same one. It has a vent hole in the top of the spicket.