COOLANT USAGE RECOMMENDATION SERVICE INFORMATION

SUBJECT: COOLANT USAGE (SERVICE INFORMATION) -----------------------------------

VEHICLES AFFECTED: ALL 1988-91 CARS, LIGHT AND MEDIUM, DUTY TRUCKS -----------------------------------------------

**************************************************************************** This information supersedes information provided in various Truck Service and Owners Manuals and should be used to determine correct coolant usage in Light and Medium Duty Truck applications. ****************************************************************************

GM Coolant specification 6038-M or 1899-M (P/N #10950998 - 10 Litres) for use in all Light and Medium Duty Trucks with gasoline or diesel engines. This coolant features a low silicate formulation and is intended only for use in engines that have cylinder heads and cylinder blocks made of cast iron.

GM Coolant specification 1825-M or 6043-M (P/N #993089) which until recently has been the recommended coolant for Light and Medium Duty Trucks has been superseded by GM Coolant 6038-M or 1899-M (P/N #10950998) in cast iron truck engines. GM Coolant specification 1825-M has a higher silicate formulation which is recommended for all passenger car engines with cylinder heads or cylinder blocks made of aluminum.

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.