One problem related to brakes failed has been reported for the 1998 Chevrolet Monte Carlo. The most recently reported issues are listed below.
The vehicle has intermittent brake failure during wet or rainy conditions. The brake pedal will go to the floor and requires pumping to get the pressure back up. We have had the vehicle to 2 different dealerships. The dealer was unable to duplicate concern has a potential for catastrophic results. An associate of mine whom is a district service manager for general motors has informed me that there is a bulletin out on the brake pressure modulator valve for the w-body vehicles. But since the part is so expensive the dealers will not root cause the component and will not perform a bulletin search.