Distribution block question -help

[Calif240]

Hey guys... I've got the majority of the brakes re-plumbed and hooked back up. I bought a brand new adjustable proportioning block to replace my old one. I'm wondering what the sensor is that hooked into my stock distribution block? I've checked my shop manuals and a few other sources and can't find the answer... From what I can tell, the brake light switch is on the pedal, so I'm not sure really what this sensor is... Please help!

[68coronetGLwannabe]

I believe its the low brake fluid or brake problem sensor which activates the brake light on the dash.

[John_Kunkel]

The switch in the block grounds out when one of the systems (front/rear) fails, the pressure differential causes a spool valve in the block to move to one side and ground the probe in the switch; this provides the ground for the warning light.

[Calif240]

So it sounds like this isn't 100% necessary? Are there any reasons I should be sure to include this in the new, modified brake system? Any thing else I should take into consideration? This is great info and is much appreciated!