89 245 "Brake Failure" light is on after recent br

[Volvo_240_Atari_2600]

Eric here.

Orlando florida
1989 245
automatic non turbo and non abs
216,000 miles

about 6 months ago, I had a hard brake pedal... There was a leak in the vacum hose to the booster so I replaced it and everything was normal... No "Brake Failure" light

About 4 months ago I replaces all 6 breake hoses, all 4 calipers and pads, 4 rotors, flushed the flud completely and bled the system. Calipers were in need of replacement and I decided to do the whole thing less the master cylinder.
"Brake Failure" light never came on before that service.

about 4 weeks ago, my pedal was going to the floor. Was getting the car to slow down and stop, but the master cylinder was gone. No "Brake Failire" lights came on either.

I bled the brakes and the car was back in business.
All parts were new or professionaly re-manufactured.

Now... a week ago the "Brake Failure" started coming on. Shut the car and re-start and the light would not come back.

This would happen about 3 times in a week.
Two days ago the lihght comes on and stays on.

Is there some kind of a sensor that could be dirty or faulty?
If so, where is it located and what is involved with its replacement?

Or could it be something worth looking into that is not a sensor?

The car slows down and stops on a dime when I apply the brakes.
I just want the light to go away if it's something silly like a sensor.

Thanks
Eric

[billofdurham]

Near to the front driver's side wheel there is a warning valve in the brake line. It is near to the manifold which splits the brake system into its tandem configuration.

Bill.

[wojeepster]

light comes on when there is a pressure differential in the lines. check for leaks then bleed the lines. piston should return to central position and light should go out.