For 1990-2009 cars

# EFFICIENT FILL COOLING SYSTEM LEAK- THERMOSTAT INFORMATION

FILLER NECK IF A COOLANT LEAK IS EVIDENT AT THE FILLER CAP, THE FILLER NECK MAY BE DISTORTED. BEFORE REPLACING THE CAP, CHECK THE NECK OPENING FOR FLATNESS AT THE CAP SEALING SURFACE. IF THE SURFACE IS NOT FLAT IT MAY BE STRAIGHTENED USING A FLAT SMOOTH BLADE (SUCH AS A BODY SPOON) AND LIGHT TAPPING. IF A FLAT SURFACE CANNOT BE OBTAINED, REPLACE THE FILLER NECK ASSEMBLY (PART NUMBER 10021199). VISUAL INSPECTION OF THE FILLER CAP SEAL SHOULD BE MADE PRIOR TO REINSTALLATION. THERMOSTAT SEAL IF THE THERMOSTAT IS REMOVED FOR ANY REASON ON EARLY 1982 "X" MODELS WITH A 2.5L ENGINE, A SWELLING OR EXPANSION OF THE SEAL MAY BE EVIDENT . THIS EXPANSION MAY PROHIBIT THE REINSTALLATION OF THE THERMOSTAT. IF THIS SHOULD OCCUR, REPLACE THE SEAL WITH PART NUMBER 3049485. BE SURE TO DIP THE NEW SEAL IN COOLANT BEFORE ATTEMPTING TO INSTALL IN THE HOUSING. DO NOT USE A PETROLEUM BASE LUBRICANT.

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.