antilock light

i have a 91 525i with the anti lock light on most of the time.
I have cleaned the sensors which i found buildup on the rears.
plenty of brake wear left. Any suggestions without just replacing
sensors which are not cheap?

Hi, Hendy- My car is older than yours, but it might have the same problem. The sensor may be fine. The problem is what is being sensed.
Your hubs have little ridges in them. As these ridges spin past the ABS sensors, they induce a voltage.
When you get some rust or dirt on the ridges, the sensor can't sense them very well. That's when the ABS light comes on.
If you haven't washed your car in a long time, do so, and spend some extra quarters to blast through the wheels. I recommend squatting down and blasting at your hubs from the underside of the car, on the inside of the rims.
As soon as they are clean, the ABS light should go out. It worked on mine!
Flunky