I haven't taken the next step in achieving braking bliss where I've replaced the hardlines on the body for the braking system.

Calipers were all rebuilt, and master cylinder replaced with rebuilt 19mm. I realize this forces pedal effort UP to excert the same force to the calipers with stock brakes.

I haven't vacuum bled the system as I only recently learned that this might be key... BUT...

How many of you have taken off the old brake hardlines and taken a look inside?

This was the key to fixing a problem on my buddies '67 Mustang GT after all the above had been done, and still no braking force no matter how hard we stomped on the pedal. The inside of the lines had knecked down from corrosion to pin-hole diameters, much like galvanized water pipe does in old houses. I don't know if this type of corrosion is typical not having stripped down more than one car to that extent.

How about tips on the pressure regulator. Are there components inside that can freeze up from corrosion? I of course, have never taken that one apart. Pitfalls or warnings before stripping it down (like tiny springs that go "ping" and fly off never to be seen again???)

Thanks