I have the 1999 F150 Supercab 4x2 4.6L All wheel disk brakes. Some time back, I replaced front disk brake pads. Good Quality Simi-Metalic pads.After awhile I noticed my Wheels turning dark from the pad dust. Worse than I would think normal. Then one day on my way to work, I was slowing down to make a turn and my brakes made a sound and the truck shook just briefly with what I would say the Automatic Brake System would do normally if I hit my brakes real hard. Then imediatly after that noise, my ABS dash light came on. It has been on ever since. Last weekend, I pulled both front tires/wheels off the truck and checked my pads and they looked fine. I found the ABS Sensor and removed the bolt. When I pulled the Sensor out of its slot, it looked exacly like I had imagined. It was completely caked with a greasy pad residue. I looked at the inside of the Rotor where the Sensor reads on the small bumps and that area was caked as well. I took my time and cleaned both the inside area of the Rotor and made the bumps area clean as new and wiped off the Sensors to clean as new. It doesn't look as tho there is any damage to any of the parts, just very dirty. Once it was clean and back together, I thought this might fix the ABS system and the light would go off. It has not gone off. I disconnected the battery for an hour or so hoping the ABS would reset on power up. But the light came back on as soon as I started rolling again.
Any ideas on how to get the ABS light to reset, or do you think something else may have failed ?
Thanks

 

Is it the yellow ABS light or is the red brake light on as well?? If it just the yellow, it has been my experience, that it is most likely your rear speed sensor. That is only a $30.00 part, and bolts ontop of the rear differential. I think that is the best place to start.

 

mud is probably right. it might just be a concidence with the front brakes. i have pulled the ABS probe on the back axle of a explorer, cleaned all the crud, and the light went out..... if a sensor is bad, or no continuity in the wire, the light comes on just after startup. if it comes on after you get rolling, that means the wires are good, but one of the sensors can not see the star wheel... check the rear. I eventually changed the rear axle oil after the light came on every month. since then (2 years ) no light.