Re: '87-5000t ABS problem

[Colin Hames <cchames@mm.com>]

> Now does anyone know if the ohm reading on the wheel sensor would be
correct if this
> is the problem.  In other words will the sensor show a reading if the rivots on the
> rotor are to far away from the sensor. Also wouldn't this kind of problem cause the
> system to shut down when the car starts moving, the computer will think the wheel is
> not moving and shut down.  My ABS light comes on as soon as I start the car.  Whas
> this the case in your situation Colin?
> 
> MAX
> 2*5KCST

Max,

	You are correct.  My ABS light did not come on until after I started to
move.  Sometimes it took only a block, other times I could make it a
mile before the system switched off.  I quess that would be consistent
with hub/sensor alignment problem.  I haven't had any other problems
with my ABS,  so I am out of suggestions.  I do know the mechanic at
Audi had some sort of pulse light he was using to measure the proper
signal.  Maybe he was measuring ohms too. 

> 
> Colin Hames wrote:
> 
> > Max,
> >
> >         I had a 88 5CST that I had the same problem.  This was the deal.
> > A Goodyear service department had recently put new tires on the car and
> > also did an alignment.  The rear was out of alignment so they used shims
> > on the rear hubs ( no adjustments can be made to the 2WD rears ).
> > Evidently you can use the shims on the non-ABS Audis.  The shims moved
> > the the sensors too far from the hub to read the wheel speed so the
> > system was switching off.  I returned to Goodyear after the dealer
> > discovered this problem and they fixed their error.  The ABS worked fine
> > after.  I did have to take the car to a body shop to have the rear
> > aligned.
> >         It might be a long shot,  but check it out.
> >
> > Colin
> > 87 5CSTQ
> > >
> > > Actually the bearings are fine, but it does remind me that the gap between the
> > > sensor and the rivets on the rotor has to be pretty exact.
> > >
> > > Thanks I need to check this.
> > >
> > > Max
> > >
> > > harrison wrote:
> > >
> > > > Check the condition of the wheel bearings. This caused the same symptom in
> > > > two of my cars.
> > > >
> > > > harrison
> > > >
> > > > Max wrote:
> > > >
> > > > > OK, bought this 5000 couple months ago and since getting it the ABS OFF
> > > > > light has been on.  I have taken readings on each of the four wheel
> > > > > sensors and they are fine, I've made sure that the shutdown switch is OK
> > > > > and can hear the relay clicking under the dash when pressing and
> > > > > depressing the switch.  Anyone have any other ideas before I give it to
> > > > > the dealer to figure it out?
> > > > >
> > > > > Max Palmarsson
> > > > > mpalmars@axxsys.com