73 dart brake problems

Heat has always worked for me. In stubborn cases I have had to drain the line.
The fluid seems to carry away the heat too fast, and if you increase the heat, you get into melting stuff. Be careful back there; the gas tank is right there,eh?
On some models the rear flex line incorporates the junction block, and it cannot be separated no how! So look carefully.
Yeah sometimes it is better to just cut out a section and put a jumper in :(

The thing you called coragated is actually a wire spring wound around the tube to protect it from gravel abrasion over the years. They're harder to crush too