Intermittent ABS Light after EBC rear rotor

[bornfrustrated]

I replaced the rear rotor with the EBC rotor (md661, beemer boneyard) with ebc pads and more I get an intermittent ABS Light flash while riding. If I tap the rear brake, it stops for a while. Everything is snug, the abs ring doesn't move on the rotor.

[Laitch]

Have you verified the ABS sensor gap measurement front and rear, and have you verified the resting battery voltage is 12.6V or above? This system can be sensitive to low battery voltage.

Front measurement


Rear measurement

[Scott_]

I know mine is an 1100, but, when I replaced my rear brake disk I did have to adjust the ABS sensor spacing a very slight bit.
Don't ask me why it would change as I moved the ABS tone ring from the old disk to the new one, but, non the less I did have to adjust the shims to get it to work correctly.

[Laitch]

An additional treatment for the symptom was described recently. The pipes coupling the ABS pumps to the system were checked for leaks. Air bubbles were emerging from one coupling. Once that leak was eliminated, the rider reset the ABS and now has experienced 200 miles without the warning light being lit during the ride.
Have you bled the ABS and brakes recently?

[Smudgemo]

See if you can realize any difference in the air gap just moving the caliper.  There is a tiny big of play in the mounts, and the shims are really thin.

My K75 started throwing lights recently.  I suspect the rear was at the edge of spec and migrated out on a long ride.  I fixed it by removing a .2mm shim and torquing the caliper mount bolts while putting pressure downward on the caliper.  I'm not quite ready to do a victory dance, but it was out of spec and the light is off now.  Don't forget to reset the system if called for.