Because it's a solid lump of rust, and rounded off too. Can I cut the hardline and splice in a length of brake line there? I think I'd need a new line--->wheel cylinder fitting as well, if I could find such a thing. The fitting on the other end of the line is just as bad so it looks like whatever I try to remove will be destroyed.

 

You can cut and splice it but it is
best to have as few connections as possible.
The more connections you have the more likely it is to develop a leak..

They make brass unions that can join two sections of line together
But I would just try to duplicate the section of the
original line in shape and length and cut and flare it if necessary..

Your local auto parts store should have what you need.
PS try some small "Vice-Grips"...

 

Gawd, I hate being such a newb!

Got a new problem: I partially stripped the threads in one of my new wheel cylinders (cuz I'm stoopid). I put Loc-Tite on the threads and it's holding for now. As I understand it, the brakes are dual circuit so if that fitting blows out I'll still have brakes at 1 front and 1 back wheel, is that right? Or will everything go? I can't get a new cylinder until Tuesday.