Hard to say if the connection is tight or not. Meeting torque specs is the determination though if it is cross treaded torque specs will not be accurate. Did you remove this line or were the symptoms prior to the brake work similar to what you have now? Be sure to use a brake/fuel line wrench.

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X5 4.6 2002 Black Sap, Black interior. 2013 X5M Melbourne Red, Bamboo interior
Dallas