<E28> ABS Problems

[Pearson-Franks Family <pearsonf@xxxxxxxxxxx>]

Link wrote:

>Date: Thu, 31 Dec 1998 17:10:11 -0500
>From: lmoser@domain.elided
>Subject: E28: ABS Problems
>
>The ABS light comes on my '86 528e at 50MPH. Long as I drive the car
>below 50mph the light will not come on but when 50mph is reached it
>comes on. What should I check for? Is this something I can fix or do I
>need to take it into the shop? Thanks for the help.
>
Larry replies:

Hi, Link!  I believe you have gummy teeth.  To elaborate, the
ABS sensors are getting bad signals, due to scum that accumulates
in the toothed, gear-like sensor on each wheel, and/or magnetic
scum attracted to the sensor itself, which is just a coil of
wire wrapped around a magnet.  If one or more of the sensors
is thus 'confused', the ABS computer senses the abberent rates
of supposed rotation, and takes itself off-line - switching on
the light.

To address this possibility, pop the wheels, then pull the rotors on
each wheel (I strongly advise having new 5mm hex screws on hand!)
so you can get to the sensor wheel.  Wire brush clean.  Then
remove the ABS sensor from the back of each wheel; I think it is
a 5mm allen.  Clean the metal scum off the tip of the sensor.
Do to all 4 wheels.

Have fun!  Larry F.

Larry Franks
Issaquah, Washington
'86 535i x 2
'83 245 GLT (Swedish iron)

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