Long story short - ABS light came on, pulled the front speed sensors and cleaned them, left front full of metal shavings. Checked pads, worn to the bone (this is the Mrs. daily driver, nuf said). Ordered new pads and installed the next weekend, pulled rotors off and cleaned reluctor wheel and sensors. On test drive brakes worked fine and ABS light went out, then flickered and came back on. Next weekend pulled the left front caliper and rotor again to check the condition of the sensor, found a small thin black o-ring stuck inside the rotor, in one of the vents. Looks like it fell out of the speed sensor? The O-ring that fits around the base of the speed sensor is green. So I removed the sensor and swagged the black o-ring goes in the hole up at the sensor tip? Did my best to reinstall but it was broken and didn't stay in place well. Would like to replace this (if it really belongs there?) There is an O-ring avail on FCP but doesn't show as fitting the 240 series (Part #: VOL-974673). Also checked/cleaned the sensor connectors (looked ok) and pulled and re-seated the two relays inside the ABS module. Test drive - ABS light went out, then after awhile came back on, flickered, went back out, but came back on for good today. Any ideas on the O-ring(s)? and what to check next?
Thanks!