GM Service Manual Online
For 1990-2009 cars only

Caution: NEVER spray water on a hot heat exchanger. The resulting steam could cause personal injury.

Notice: Compressed air or water can be used to clean the radiator fins. Do not exceed 138 kPa (20 psi). Pressure over 138 kPa (20 psi) will damage the radiator.

Clean the front of the radiator at least once a year. Blow through the radiator from the rear towards the front of the vehicle with compressed air, in order to remove bugs, leaves, etc. If compressed air is not available, you may substitute water using the same procedure.