Brake warning light stays on

[85burb]

So sometimes my break warning light stays on. If i push my park break down the light is much brigther. So i got under dash and inspected the park break switch. It seems to be working fine. So i unpulged my proportioning valve on the front cross member and the light went out. I hooked a jumper wire from the wire that plugs in to the proportioning valve and groung and the light came back on. I put my volt meter on the valve and i showed 140 ohms or resistance from plug on valve to ground. My breaks are not leaking and it stops great. It all started when i washed my engine bay a few weeks ago. Sounds like the senser on the valve is bad or whatever. I have looked for the valve on autozone, oreillys, lmc and cant seem to find one. Are they still made or am i looking at this wrong?

[72lb4x4]

If you get a leak in a brake line, (or bleed them w/o locking the pin in place) the pressure is unequal between the front and rear so the switch on the block by the MC is turned on, making the light come on.

Did you bleed the brakes recently?
Low on fluid?
Bad brakes?

The light is saying you have brake problems.

[85burb]

It comes on sometimes and sometimes it wont. I pressure washed the engine bay on day and it has jacked up eversence. I dont have any leaks just checked that. Fluid is full. Pedal is hard as rock so no air in it that i can feel. The light is no bright it is kinda dim. I have never heard of the pin you put in it to bleed the breaks.

[1LowToy]

Check the rear brakes for wear and adjustment, bleed the system. My brother did the same thing, removed the wire then ran for about two months. Then he asks me about this horible grinding noise when hen applied the brakes.

[85burb]

I have redone all 4 wheels with in 3 mounths. Pads, rotors, calipers, durms, hardware, shoes, cylinders, even cables. The only thing i did not replace is the hoses and master cylinder. What is this pin that you are supposed to install befor bleeding the breaks? Maybe i will try bleeding it.

If i understand the operation of the valve the light should only come on if i have pushed the breaks. Then the little valve or what ever will move and block off some passeges and set the light. When i start the truck befor i ever push the breaks the light is on. I can drive around and the light will go off. If i restart the truck sometimes the light will come back. To me that sounds more like an electrical problem then a issue with the breaks. I will try to bleed them tomorrow maybe and see if that helps. Just need to know what the pin is that is supposed to be used.

[Corts60]

My light was doing kind of the same thing and I ended up just replacing the proportioning valve and then it stopped.

[72lb4x4]

You don't install a pin. Got a manual? It explains it better than I can.

In the end of the block by the MC there's a rubber plug. You're supposed to put a little bracket on to make sure the pin, shaft, whatever it is doesn't slide out too far when bleeding.

Anyway, it sounds like maybe the wiring got wet.

[old Rusty C10]

mine was doing the same thing but it was a totally different thing. mine the spring that holds up the parking brake pedal is weak and the light goes off when i push the pedal up with my foot. Temporarially ive tied it up with a wire but the unit needs replacement
Yours appears to be more of a proportioning valve issue but i decided to throw this out there just in case

[85burb]

At first i had thought it was the park break switch. But with the prop valve unhooked the light says off unless the park break is set.