I connected to the antifreeze fill side and had the valve to the tank at the pump open. Heard the tank filling and shut it down.
On the other hand It is a mess free way to fill if you chose too.
I did this on my Roo. Just make sure you don't fill faster than it can vent, or you'll blow up your FW tank!!
1988 Coleman Sequoia - popup (1987-2007)
2012 Roo19 - hybid (2012-2015)
2016 Mini Lite 2503S - tt (2015 - ???)
2011 Traverse LT, 3.6L, FWD
2009 Silverado Ext Cab, 5.3L, 4x4, 3.73
2016 Silverado 2500HD Dbl Cab, 6.0L 4x4, 4.10