Air Brake Antilock problems of the 1998 Chevrolet Silverado

The anti-lock brake system fails on dry pavement when a bump or separation is contacted in the pavement during the braking operation, resulting in lost of braking capacity. This occurs usually between speeds of 25-35 mph during braking while the vehicle is slowing down. If during that time, a bump or rise occurs in the pavement, it seems like traction is lost and braking capacity is diminished, resulting in increased stopping distance. Often this occurs at stop signs and intersections, occasionally when attempting to turn, resulting in hazardous handling. Dealer has been notified several times, and attempts to repair by replacement of gasket on fluid reservior lid of master cylinder dimished the symptoms but did not rectify the problem. Hazardous braking situations continues when brake failure and/or increased stopping distance on dry payment occurs.