My Focus has a 12 inch metal brake line that goes into the rear wheel cylinder, and it was rusted and looked like it might rupture. I purchased two new lines at Auto Zone. I took a piece of number 12 copper wire - removed the insulation from the wire so it was bare copper, and pushed it through the new steel brake line. Then I bent the brake line - like superman - with my bare hands in the same shape as the original and then pulled out the copper wire. The wire inside the brake line prevented the steel tube from kinking and I was able to get a perfect fit. Then I had to bleed the air out of the line. Adding that piece of copper wire made the job easier.