The problem wasn't following the instructions--the problem was using a syringe! I couldn't seem to get the syringe to fill up. It took forever. One syringe that I was using had a "removable needle". I tried pushing so hard to get the liquid into the fill hole that the needle popped off and juice was everywhere. I've just never had use in my life to learn how to use a syringe and it works so much differently than on the Dr.'s shows. (I never saw Dr. Kildare splash medicine all over himself while preparing to give an injection!)
LOL, I didn't mean to imply you weren't following instructions. I need to take the time to read things closer. My apologies! Being old, ya gotta forgive me. Everyone else does ... sometimes.
Okay, take the needle off of the syringe, fill the syringe then put the needle back on. I keep a tiny pair of needle nose pliers handy for getting them on tight and then getting them back off again. Believe me, I've blown e-juice all over the place until I started doing that.
When I fill the carto, I do it slowly and keep a thumb and index finger on the top of the needle ... just in case. But doing it steadily and slowly is the secret and of course, getting it back on tight.