One problem related to brake drum wheel cylinder has been reported for the 1999 Volvo S80. The most recently reported issues are listed below.
Brake pedal was slowly going lower before braking occurred. Original problem was "fixed" by service on 8/22/00, but service manager stated car needed a new master brake cylinder, which was supposedly ordered. Problem began to re-occur on 9/22/00, and car was delivered to service on 9/26/00. As of now, it has been there 3 days to install a new master brake cylinder, originally described as a 1-hour procedure. Supposedly the replacement installed yesterday, also had the same problem. As of now (after 5 p. M. , 9/28/00) the service department is unable to definitely state the problem has been fixed - - and there may be a serious problem with Volvo master brake cylinders (and their availability).