Brake issues - Help, PLEASE!

[Dub Nizzle]

Newby here. Purchased an '87 GN with a little under 52K on it back in March. During the test drive, I noticed that the brakes were "spongy" and that the "Brake" light within the dash would illuminate for a brief second. I just assumed that it needed a good flushing and bleeding. Performed that work about 200 miles ago and when I sat in the car this a.m. to drive into work, I had very "stiff" brakes (that wouldn't bite) and the "Brake" light on the dash is on the entire time I have my foot the pedal.

What's the issue?

Thanks in advance for your assistance!

 

[lolo86GN]

Probably need to replace something on the powermaster unit... powermaster uses and electric motor to fill an accumulater ball for braking assist. From what I know of them, they are prone to all kinds of failure and most people will opt to replace them with vaccum brakes or hydroboost systems... I actually just got done with a hydroboost system on my car this weekend and am very happy with the results. It may be something as simple as changing the pressure switch, but I think most people will agree that changing to a different setup would give you much more piece of mind..