Brake light flashing 5kcs

[John Larson]

I've seen cars with the lingering "Brake" warning even with a new
accumulator.  My 20v does this.  Replacing an expensive accumulator that
passes the 20+ pump test isn't something I'd even consider.  The frequency
of leaking/failing warning switches is high, and they're cheap.  Without
testing the pressures, it's difficult to determine the source of any brake
boost system failure.  In this case, we're not even sure which system is the
problem.  Is it the brake system or the booster system?  Is it fluid level
or pressure?  With the report of an overflowing reservoir, but also the
absence of a sender, is the warning light even related to the boost system?
John
----- Original Message -----
From: "Fred Munro" <munrof at sympatico.ca>
To: "John Larson" <j.d.larson at verizon.net>; <mannix at rmsolo.org>;
<quattro at audifans.com>
Sent: Friday, November 23, 2001 6:39 PM
Subject: Re: Brake light flashing 5kcs


> Hi John;
>
>     I had two indications the bomb was dead on my '91 200q. The light
stayed
> on for over 30 seconds after I started the car (bomb discharged and
> repressurizing), and the light flashed under heavy braking (system
pressure
> too low). The bomb had 3 pumps in it. Replacing the bomb eliminated the
> light issues. The car braked normally, but fortunately I had no occasion
to
> stop in a hurry.
>      If the bomb is more than 7 years old, I'd tend to suspect the bomb
> before failure of the other components. Without the backup provided by the
> bomb, it is possible to pull the system pressure down below the warning
trip
> for the light with the engine running if you brake hard enough.
>
> Fred Munro
> '94 S4