abs engaging during normal driving

[Brett Dikeman]

At 8:51 PM -0700 3/24/03, Jeremiah Curry wrote:
>Howdy all,
>
>I just got my 91 200 20v back from the shop where I got a tune-up, new power
>steering pump, alignment, and thermostat. (ouch to the tune of $660)  Now
>the abs engages during normal driving, especially really slow stops.  It
>makes that clanging sound and I can feel the brake pulsate.  If I defeat abs
>with the dash buttom the problem goes away.  Any ideas.

I'd say take the car back to the shop that did the alignment and ask
them to re-seat all the ABS sensors and/or plug in the ABS computer
diagnostic unit if they have one(they probably don't.)  It sounds
like one was jostled, perhaps?  The "activates at slow speeds" is a
common problem when one or more sensors aren't properly spaced from
the teeth on the hub, usually too far I believe.

Proper procedure involves a set of small plastic caps that go on the
end of the sensor; you replace the cap, push the whole thing back in,
and the teeth on the hub chew away the plastic as soon as you drive
it, leaving a perfectly spaced sensor.  They're commonly called
'ablative caps', and you should be able to find a number of posts
about them in the archives(including some possible part numbers) if
you plug that into the archive search.  They cost about $1/apiece.


>In a seemingly unrelated issue I have noticed a clicking sound, like tirm
>signals but faster that comes on sometimes from what sounds like the area
>behind the vents by the drivers door.

It is possible they're related.

In any case, if you're positive it is not coming from the fusebox in
the engine compartment, that'd be one of the auxiliary relay
panels(either the one in the side kickpanel, or the one behind the
knee panel.)  A common source of clicking is accidentally bumped seat
heater controls, but if it's faster than a turn signal...

   Your best bet(provided no accessories are going bonkers) is
probably to remove the panels and feel around until you can find the
relay that's operating and check to see what it is in the Bentley.
It will be obvious when you've found the right one.  Might want to
start with the lower kickpanel, or try and pinpoint it more; the knee
panel is more of a pain to remove- you have to take off the end 'cap'
on the dash, and then remove about a bunch of torx and phillips
screws.

Brett
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