I have a '99 F150. Today I did a front brake job (rotors and pads), and afterwards the ABS light started coming on. I did not do any work on the rear brakes.

If I turn off the truck and restart it, the light is off, but after several seonds it comes back on, even if I do not depress the brakes. If I do depress them, it comes on faster.

The light was not on prior to doing the front brake job.

Any ideas what might have started the light coming on or what to try to turn it off?
(I saw in several post here mention of resetting the computer, but did not see how to do it. Can anyone tell me how?)

Thanks for the help.

 

the magnetic speed sensor on the hub (knuckle) might have a piece of rust or dirt stuck to it. Did you bleed the fluid or open the bleed screw?

 

You may have gotten non-ABS rotors. Do your new rotors have the abs ring installed? Compare the old to new on the inner side. The ring is around the hub and has a scalloped shape.

Here's a rotor from my '99 w/ 35k miles.