98 Outback ABS activating on every stop

[levi1998]

My 98 outback (104K miles) has just developed this interesting feature
where it kicks in the antilocks every time I stop. Once the speed
drops below about 10mph the brake pedal starts doing the abs pulsing
thing. These are gentle stops on dry pavement so it is NOT a
situation where the antilocks should be activated. It happened very
consistently at every stop on the way to work tonight. So far no ABS
light though...

Any thoughts as to why 10 mph should set off the antilocks on an
otherwise normal(non-panic) stop?

 

[Josh Assing]

Dunno reasons; but I'd look at warped rotors.

My 98 outback (104K miles) has just developed this interesting feature
where it kicks in the antilocks every time I stop. Once the speed
drops below about 10mph the brake pedal starts doing the abs pulsing
thing. These are gentle stops on dry pavement so it is NOT a
situation where the antilocks should be activated. It happened very
consistently at every stop on the way to work tonight. So far no ABS
light though...

Any thoughts as to why 10 mph should set off the antilocks on an
otherwise normal(non-panic) stop?

 

[Jim Stewart]

My 98 outback (104K miles) has just developed this interesting feature
where it kicks in the antilocks every time I stop. Once the speed
drops below about 10mph the brake pedal starts doing the abs pulsing
thing. These are gentle stops on dry pavement so it is NOT a
situation where the antilocks should be activated. It happened very
consistently at every stop on the way to work tonight. So far no ABS
light though...

Any thoughts as to why 10 mph should set off the antilocks on an
otherwise normal(non-panic) stop?

No, but I should think that Subaru would be
very interested in looking at it.

 

[Alan Ronemus]

The ABS system does a self-test on startup, so it's probably OK if you don't
have a warning light; however, you could have a problem with a wheel sensor or a
tire that's worn enough to cause a difference in rotation speed. Take a good
look at your tires and measure the circumference of each (they should be very
close), then look for wear, dirt, corrosion, damaged sensor, etc. A cleaning
may be all that's needed if you've got mud, salt, etc. caked in the wrong spot.

 

[Henry Paul]

Are you sure it is the ABS system and not warped rotors causing the pedal to
buck under your foot?

 

[levi1998]

I have removed the ABS fuse and when the car stops it feels fine. By
that I mean there is no indication of warped rotors. Feels like it
always has.

What kind of PSI differences are we talking to make a diffence? I use
a digital gauge so the pressures should be within 0.5psi worst case...

Seems a bit extreme to have to set tire pressures by wrapping a string
around the tire. Anyone else found this extreme level of sensitivity?

thanks

 

[Henry Paul]

For the tire pressure I run my tires a little higher. I like a firmer ride
and a little better mpg so I run 45psi front/40 rear.