Have you verified that line is actually bad/leaking? I had to replace the Hydro-Boost unit on my 2002 GT a little over three years ago, because my power steering pump started groaning, due to low fluid level. I also had a soft brake pedal, but I think that was a result of the incompetent shop I paid $400 to install my Hawk Sector 27 brakes pads and drilled/slotted rotors (I'm a tractor-trailer driver, and was living at the time in an apartment where it wasn't possible for me to do work like that on my car), and Wildwood stainless steel flexible brake lines. They were at first going to let me take the car with a brake pedal that went almost all the way to the floor, then after keeping it another four weeks with little improvement (they took it to Lincoln dealer who bled the ABS pump), I finally got fed up and took it home, intending to fix the problem myself. That problem, I believe, was they damaged the internal seals of the master cylinder, by pushing the pedal down too far when they bled the brakes multiple, multiple times (age of the master cylinder, I'm sure, was probably also a factor).
Anyway, I couldn't find any source of power steering fluid leaking, until I checked my carpet, under the dash - fluid was leaking down the firewall and going under the carpet, getting that rubber covered insulation under the carpeting wet. So, you might wanna check under the driver's-side dash for any fluid leakage, as well as in the engine compartment, directly under the Hydro-Boost unit.
I replaced both my Hydro-Boost unit (I got a brand-new Motorcraft unit from Amazon) and master cylinder (Raybestos) at the same time; bled the brakes and power steering system, and my brakes have been fine ever since.