Metal brake line nut won't budge....

[HuskyMan]

Working on the 1991 560SEL. Installed new brake lines recently so I'm unsure why the metal brake line nut won't loosen easily. I sprayed it using PB Blaster, waited twenty minuted and it still would not budge. I then using a syringe to inject with KROIL oil so we'll see if that will do the trick. I'm using a 17 mm line wrench to hold the nut on the rubber brake line and an 11 mm line wrench to try and turn the metal brake line nut.

Any ideas to help me out with this are appreciated.