Try it again but be sure to purge the onboard tank first by pulling the check valve. Replace the check valve, turn the green can upside down first and turn on to make sure you are getting liguid /gas coming out before connecting to your check valve, then connect up and fill your tank. Clear line is best so you can see what is going on. You can get clear 4mm line from McMaster for about 17 cents a foot. I have the part number if you need.
BC