One problem related to power assist brake vacuum has been reported for the 2000 Volvo S80. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2000 Volvo S80 based on all problems reported for the 2000 S80.
A hissing sound coming from the brake pedal area began occuring and I took to the car to the dealer and was informed that it was a defective "brake booster" and that it is a very dangerous situation that if not corrected could lead to total brake failure. The car is used twice a week and the brake booster has not been replaced and is available for inspection.