Brake System light revisited

So I'm building a 1970 Dart and completely (and I mean COMPLETELY) replaced the brake system. It's a factory KH front brake system wiith 10 inch drums out back. When you start the car the Brake System light comes on on the dash. When you put moderate pressure on the pedal it goes out. It's this last part that is new (just started test driving it this week). I know there is a piece in the distribution block that is supposed to be centered and when you have a partial system failure the light comes on to warn you. The brakes seem to work well and I can't find any leaks. Suggestions??? If all else fails I'll return the valve to Classic, but it was a pain getting the system all sealed up in the first place and I'd rather not start all over with the multiple fittings in the block.