My bad... Let me try this again....
I have a 1977 Corvette (just like the one pictured and mentioned on my profile page).
To keep the post somewhat short; When I bought the car (about a year ago) the brakes were a little spongy. I saw that they were leaking fluid on the inside front tires and figured it would be nothing more than a (simple) brake job...
Finally having the time to take care of this (long story short) I replaced the front calipers. The bleed job went as smooth as any of the other bleed jobs I've done in the past 30+ years (just saying, NOT my first time bleeding brakes).
With firm pressure on the pedal and big smile on my face (finally get to do a little power braking burn out for the Facebook page), I started up the engine and hit the brake pedal and squissssh.... all the way to the floor they went.
Back to the drawing board I went. All four tires off now and did the full blown bleed job (passenger rear inside, outside, driver rear inside, outside, passenger front, driver front.) Once again, great pressure on the pedal until I fired up the engine.
I did manage to get the brake light to go out by doing some minor power braking... Back breaks hold as good as one would expect, front are not holding at all it would seem. With my foot on the brake and in gear the rear end will squat real low (which is kinda cool looking) but give it enough gas (not talking a lot here) and there's just not enough brake to hold it in place. By doing this, it becomes obvious to me the back brakes are doing their job and the front are not .... at all it would seem.
I jumped on the vacuum assist (brake booster) because "vacuum" seems to be the only difference between engine on and engine off... after doing some reading, it doesn't seem that what I have described would be caused by the booster going bad (my brakes should be harder to push with a bad booster.... right?)
I have seen some talk about a proportioning valve/switch... going to go take a look see now.
So much for keeping this short...
Any help will be appreciated.
Click on picture for closer look!