My filters must be filled when installing on the Cummins 8.3L mechanical.
I have a Toad following the MH.
If I for some reason needed diesel fuel for an emergency filter exchange, I would put a quarter over the center hole of the new filter and pour the fuel from the old filter into the new filter.
If that were not adequate, I would drive to the diesel station and get some diesel fuel in some type of container and bring it back to the rig.
In 13 years and 70,000 miles that has never happened.......
1995 CC Magna #5280
C8.3L 300hp Cummins, 31,000lbs