Audi 5000 Question. 85?

[James Steele <avon@ritz.mordor.com>]

THere is an Audi 5000 that I am responsble for maintaining.  This car 
runs...suitable, except for one major annoyance. The light for the brake 
systems (Power steering fluid, something, I don't ahve the manual in 
front of me).   Sounds every time I hit the brakes!  Exactly what is 
this?  Burned sensor, burned pump?  Or something compplicated.  I have 
the Haynes manual, it makes no mention of this.  Comments and suggestions 
are apprecaited.