Brake Warning light stays on!

[1of1.000.000]

Heya everyone, need a hand here with a question. Well several weeks ago I was driving in the rain and my CHECK BRAKE light came on. Got to work and noticed the resevoir was low, barely anything in it. So I topped it off and drove home after work. Braking was horrible and light stayed on. When the weather dried up I noticed my back wheel cylinder apears to have been leaking a bit and splattered on the tire inside. Eventually from driving it the brakes started to function quite a bit better. However the Brake Warning light is constantly on. Does anyone know why it's on and how to reset it or turn it off? I have not fixed the wheel cylinder as of yet.

 

[94Sierra4x4]

Fix your leaky cylinder, I *think* when the brakes build up vacuum pressure the light goes off.. not enough vacuum, light comes on.
Which is why the brake light comes on when truck is off, with the key in on position.

that's how I see it anyhow

 

[MSCustoms]

What year is the truck? I have a 90 and the brake light stayed on and I still had plenty of brake fluid in the master cylinder. It turned out that it was a brake code, basically the check engine code version for the brakes.

 

[92gmc4x4]

replace the rear wheel cylinder, my brake lights stayed on constant on mine because of the abs, so i removed it lol

 

[zilverado71]

Replace Wheel Cylinder. Top off fluid. Remove STOP fuse in cabin for 15 seconds. Reconnect and start vehicle. Your welcome.

 

[1of1.000.000]

What year is the truck? I have a 90 and the brake light stayed on and I still had plenty of brake fluid in the master cylinder. It turned out that it was a brake code, basically the check engine code version for the brakes.

I've heard of this as it had been flashing when my brake lamp switch needed to be reset after off roading one time. It's just been so dreadfully cold I haven't wanted to do the wheel cylinder. It is a 1990 K1500 which I forgot to mention. I am going to try the stop fuse and see if that resets it for the meanwhile. Thanks to all BTW!

 

[MSCustoms]

IIRC you connect two of the pins on the data link connector at the bottom of the dash and the light will flash just like the check engine light with the code reader

 

[zilverado71]

Lastly, the brake light indicator is also a trouble code for some other items in the truck. For example, if its flashing, a certian number of flashes means your speedo is not working. The STOP fuse resets anything pertaining to this sequence.

 

[Darkrider]

Hmmm will have to try the fuse trick on my 1 ton when it warms up. I had the brake light kick on after getting sideways in it one night...me thinks the ABS didnt like that lol