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Re: Brake Warning Light

-----Original Message-----
From: Bruce G Plante <Bruce.G.Plante-1@tc.umn.edu>
To: quattro@coimbra.ans.net <quattro@coimbra.ans.net>
Date: Sunday, November 29, 1998 12:49 PM
Subject: Brake Warning Light

>I am currently the original owner of a 87 5kSQ with 160k on it.  Lately, I
>have experienced two problems:
>1)Brake Warning Light (the red triangle! from the auto check system) comes
>on temporailly during some brake applications at low RPMs and then goes
>Dealer said it was common for older pumps "temporary reduction in
>The warning sound is bother some however and I would like to disconnect if
>possible.  Removing the connection from the hydraulic expansion tank and/or
>brake fluid reservoir does not do it.  Any thoughts?  Does any one know how
>to disconnect this sensor?

Bruce, DO NOT DISCONNECT THIS SENSOR! You have a problem with the braking
system, most likely a bad pressure accumulator (bomb). If this is the case,
you can run out of brake assist, making the car dangerous to drive. My '91
200q started to show the same symptoms (the red "brake" warning light came
on under heavy brake application) and the problem was a bad bomb. You can
test the bomb by running the car until the light goes out, then shut off the
engine. Apply the brakes until the pedal gets hard, counting the
applications. A good bomb will give 30-40 applications and you should get at
least 20. A bad bomb may only give you one or none.

>2)Driver side power mirror works to tilt mirror left to right but not front
>to back.  When pushed to move front to back it still moves only left to
>right.  Diagnosis and prescription?

    Pull the switch and use a multimeter to confirm the up/down contacts are
making a connection. If they are, pull the mirror glass off and check the
clutch and connections. On your car, you have a single motor in the mirror
and a clutch system which determines which drive set is engaged. The newer
cars ('89-91) eliminated the clutch and use two motors.


Fred Munro
'91 200q  262k km