1973 chevy c10 parking brake light

[watonka]

On my 1973 i have replaced both front brake calipers and taken apart and reassembled the rear brakes and checked the parking brake cables and am about to replace the master cylinder. My brake light is still illuminated on the dash. Is there a sensor or some other techincal piece to check to turn that light off. I have checked the emergency brake in the cab and i can not find anything that makes that light iluminate and i want it off if it is not engaged. Any help would be greatly appreciated.

 

[75gmck25]

There is a brake proportioning valve mounted in the brake lines, located on the drivers side near the lower corner of the fan shroud . It’s a small metal block with all the brake lines connected.

The prop valve has a one-wire electrical connection in the middle, connected to a small plunger/pin. If brake pressure is too low on either front or rear (big leak, etc.) it moves the plunger all the way one direction, and turns on the brake light.

Once you get all the brakes fixed and bled, you can usually recenter the valve and turn off the light by getting up to about 25 mph and stomping on the brakes a few times.

 

[cstew47]

I believe there is a plunger reset on the end of the valve body

 

[disenough]

I wound try what 75gmck25 suggested first. The reset plungers usually start leaking after pressing them.