HELP! Brake light on! Pedal hard, tried everything.

[grayw0lf]

Ok, so I recently put 6 lug disc brakes up front & I'm to the point where I want my drums back. Earlier I had a bad reman master cylinder, that problem is resolved. 71 style MC & used prop valve.

Now my Brake light comes on after I stop quick. The first time or 2, it goes off, then stays on. The pedal gets hard when the light comes on. Doing about 25mph downhill, I am unable to lockup any wheel. I've bled the brakes more than once.

Question1 - What gives? What am I doing wrong? Bad prop valve? (its the only thing not new).

Question2 - What does the brake light sensor signify? What exactly is it measuring?

I'm at my wit's end. Thanks for your response.

John