'90 Grand Caravan, brake line replacement

The NE salt finally got to my brake lines. I want to install new lines and the fittings at a "manifold: are badly rusted. I see what looks like a manifold with 2 lines in and 2 lines out about midway along the "frame" rail. Does anyone know what this manifold does? Is it a safety device? Seems connected to some sort of turnbuckle.

Any help on brake line replacement would be helpful. The spiral wire wrapping has rusted/fused itself to the inside tubing.