Re: ABS Weirdness

["Doyt W. Echelberger" <Doyt@nwonline.net>]

>To: gholton@us.ibm.com
>From: "Doyt W. Echelberger" <Doyt@nwonline.net>
>Subject: Re: ABS Weirdness
>In-Reply-To: <85256836.004BF04B.00@D51MTA07.pok.ibm.com>
>
>I hope you come up with an answer.  My 87 5kcstq is doing the same thing.
My mechanic hooked it up to his $10,000 ABS diagnostic instrument and it
checked out OK. But it keeps going "Brrrrttttt" in the last half second of
a stop.   And it doesn't do it every time,  maybe 50%.
>
>I'll bet if we give this thing some publicity on the list, someone will
come up with a BTDT.
>
>My most recent idea is that it is related to the condition of the 'bomb,'
or has something to do with a fault in some component of the hydraulic
system.  I say this because I started having the triangular yellow brake
symbol appearing at the start of this problem.  At first, the symbol only
came on randomly, and would go away when I stopped and restarted the
engine.  Now the symbol comes on when I start the car and never goes away.
And I get zero pumps from the brake pedal before it hardens, when the
engine isn't running.
>
>I have a replacement bomb ordered and figure it will get here next week
and be put in. That should bring the ABS back to normal operation if my
hypothesis is correct.
>
>I'll be sure to post if this happens according to plan.
>
>Doyt Echelberger
>87 5kcstq
>>>>>>>>>>>>>>>>>>>>>>>>>>>>
>At 08:49 AM 11/27/1999 -0500, you wrote:
>>I've never owned an Audi before, but recently bought a 1987 5000 CS TQ for
>>my daughter, which I'm in the process of fixing up.  When I bought it, the
>>ABS
>>would engage at the end of a normal stop, when rolling about 5 MPH.  The
>>previous owner said that the wheel speed sensors needed to be aligned and
>>gave me a set of plastic caps to do the job.  After installing 3 of the 4
>>caps, I
>>needed to drive the car and noticed that the symptoms that I'd had before
>>were
>>gone, but the ABS OFF light kept coming on.  It would stay off for a minute
>>or
>>two after cycling the switch off/on, them come back on.  That tells me that
>>the
>>ABS computer thinks it knows whether the system is sick or well.  After
>>aligning the 4th
>>wheel sensor, the light stayed off, jitters still gone, but the system
>>doesn't seem
>>to be working.  When I stop on a slick surface, I get skidding and there
>>seems to be
>>no differencein behavior with the system switched on vs. off.   Is there a
>>sensitivity
>>adjustment somewhere?  Any ideas?
>>
>>
>>