Randomly activated ABS issue (1 Viewer)

[JBMcG]

I recently purchased a 2002 Sequoia with 223k miles. I've put maybe 500-600 miles on it with no issues, until yesterday when I was driving down a declining paved road at about 40MPH and applying light brake pressure when it seemed like the ABS activated, randomly, for maybe 5-10 seconds. I felt slight vibration in the brake pedal and heard a something between a hum and a faint growling sound. Could not get it to duplicate on that road or anywhere else.

I'd read it could be a dirty ABS sensor/Wheel Speed Sensor so I checked all four. The left and right front sensors looked like this, so I cleaned them up, cleaned mating surfaces and reinstalled.

The rear sensors were pretty fouled with ground metal, as pictured below:

I cleaned them up, and reinstalled. I still haven't been able to duplicate the random ABS activation (if that's what it was).

I'd also read the metal shavings could be sign of bad wheel bearings. I couldn't find anything in the maintenance history indicating rear wheel bearings had been done. I didn't see other obvious signs of wheel bearing issue.

Any thoughts or insights would be highly appreciated!

 

[efjayatee]

Any CEL on your dash lit up? VSC, slip indicator or TRAC

 

[JBMcG]

Any CEL on your dash lit up? VSC, slip indicator or TRAC

Thanks for the reply. No, no lights. Just that weird behavior that one time. I've probably put 50-75 miles since then. Need to drive it more. I'd also seen some info suggesting the axle seals tend to allow water intrusion which can cause rust/gunk. Since there didn't seem to be other obvious signs of wheel bearing issues, I'm wondering if that's the culprit. Or, might it just be beginning stages of wheel bearings going out. Again, I'm assuming 223k miles on those bearings.