Four problems related to brake master cylinder have been reported for the 1998 Chevrolet Silverado. The most recently reported issues are listed below.
Around 45 mph there is intermittent brake failure. When applying brakes vehicle starts to slow down. Then, braking action stops, pedal feels spongy. Vehicle taken to dealer 3-4 times, master cylinder was replaced, did not remedy the problem.
Brakes-master cylinder.
When the brakes are applied the light comes on, vehicle pulsates and vibrates . Dealer has replaced the master cylinder /pads, and reserfaced the rotors . Manufacturer has been notified.
When the brakes are applied they become spongy and weak. The pedal goes to the floor , resulting in extended stopping distance. Has had the master cylinder and the brake pads, and various other parts of the brake system replaced twice. The manufacturer has been notified.