93 Ford ward amtran 5.9 Cummins

[Patchwork]

Today I changed the back left brake cylinder after replacing and removing brake line I cannot get for the life of me the brake line back in the new one I have no idea why it will not fit I've tried taking out all the bolts and moving at every angle I've tried installing all three bolts and again start trying to install the brake line to no avail what is going wrong how is this so hard what am I doing wrong it should be real simple I know any ideas could the nut on the brake line somehow be messed up? Cross threaded? I'm really at a loss guys.