Field reports indicate that dealers are changing the new oval "O" rings on the suction/ discharge ports on 1989 vehicles with R4, V-5 and HR-6 compressors.
Harrison Radiator changed to the new "Oval" design "O" ring for the suction/discharge ports at the start of production 1989.
Do not use 1988 "O" rings on 1989 vehicles. If a new oval "O" ring is needed, the part number is 6558587. Parts are currently available through GMSPO. The Delco part number for the new oval "O" ring is 15-3886.
General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.