Phantom ABS activation after rear bearing replace
 

Just replaced a rear wheel bearing on my 2009 Civic EX. Now I get semi-random ABS activity under light braking on dry pavement. No ABS light, and brakes are fine. ABS activity is very light and brief, may happen once or twice, or not at all on any given stop. Doesn't seem to happen under hard braking, though I haven't tried enough to be positive.

Looking at the bearing assembly, I don't see the toothed gear that I'd expect. Not sure what the ABS sensor is supposed to pick up, and no idea what's causing the bogus ABS activation. Any thoughts?

Re: Phantom ABS activation after rear bearing replace
 

If a shop did it, take it back

Re: Phantom ABS activation after rear bearing replace
 

If a shop had done it, I would have taken it back in a heartbeat. I need to figure out if I might have done something wrong (hard to imagine what in this case - pretty simple job as far as I can see) or if I need to send the bearing back.

Re: Phantom ABS activation after rear bearing replace
 

Assuming the ABS sensor is not damaged.....The magnetic encoder ring is probably damaged or weak. Replace bearing/hub assembly -- again (warranty if possible)

I strongly urge you to use a part sourced from a Honda dealer.


KEEP IT AWAY FROM MAGNETS!
The encoder ring is a magnetic strip embedded in one of the bearing seals. It is very susceptible to damage from close proximity to magnets. You can't see the damage by eye but there is a tool that can show the magnetic fields in the ring.

http://ww2.justanswer.com/uploads/PE...453_156409.gif

One possibility is the ring is damaged magnetically. The cheezy little magnet in a pocket screwdriver can ruin it.

Another possibility is weak magnetism in the ring...Its pattern could still appear ok when using that tool above, but that can't determine the magnetic field strength.
Seems likely if you used aftermarket part.


Again, I strongly urge you to use a part sourced from a Honda dealer.

Re: Phantom ABS activation after rear bearing replace
 

Well, that makes sense - wondered if that's how it worked. Part should still be under warranty.