Certain sport utility vehicles, pickup trucks, and passenger vans fail to comply with the requirements of federal motor vehicle safety standard no. 135, "Passenger Car Brake Systems". Some of these vehicles were produced with an out-of-specification brake hydro-boost housing relief valve bore.

Consequently, the valve o-ring seal may fracture. Steering efforts may be slightly increased while braking or parking. Under certain driving conditions, a fractured seal may require a slight increase in the applied brake pedal effort to achieve the same vehicle deceleration rate as prior to the seat fracture.

GM has not yet provided a remedy for this campaign. Owner notification is expected to begin during the second quarter of 2004. Owners should contact GMC at 1-866-996-9463.

Certain vans fail to conform to the requirements of Federal Motor Vehicle Safety Standard No. 209, "Seat Belt Assemblies." These vehicles may have been produced with seat belt buckle assemblies containing a latch with a brittle condition that may not withstand the force requirements of the standard.

The safety belt may not restrain the occupant as intended during a crash, which could result in injury to the occupant

Dealers will replace the safety belt buckle. Owner notification is expected to begin during May 2004. Owners should contact GMC at 1-866-996-9463.