If you have the original take a peek at it. Make sure the flare on the original is the same as what you are making. You didn't say what kind of vehicle but some use that bubble flare. There are also 2 different flaring angles, make sure you are using the proper tool. The flare on the line and the block need to match.
Standard is 45* AN is 37*
Artificial Intelligence is no match for Natural Stupidity