Do not remove the radiator cap in order to check the coolant level. Check the coolant level through the cap level indicator of the recovery reservoir or through the semi-transparent coolant recovery reservoir every time the hood is up. When the system is cold, the coolant level should be near the full COLD mark.

When the vehicle is at normal operating temperature, the coolant level should increase to the full HOT mark. Add coolant to the coolant recovery reservoir only in order to raise the level to the full HOT mark. Use a 50/50 mixture of GM Goodwrench DEX-COOL™ (orange colored, silicate free) coolant, GM specification 6277M (or equivalent), and clean water for coolant additions. Preferably use distilled water.

Ensure that the GM Goodwrench DEX-COOL™ coolant, GM specification 6277M is orange and not green. This coolant is orange in order to distinguish it from green coolants using silicate/phosphate based inhibitors. Examples of these coolants are GM 1825M and GM 6038M. Do not mix the orange coolant with the green coolant in vehicles.

When servicing a vehicle that requires GM Goodwrench DEX-COOL™ coolant, GM 6277M (or equivalent), use only virgin coolant. When servicing a vehicle that requires the green silicate/phosphate type coolants, use only the specified coolant that is either virgin or recycled, as permitted.

Supplemental inhibitors or additives that claim to provide increased cooling capability are not necessary if using the recommended antifreeze. Additives may be detrimental to the efficient operation of the system.

Always maintain the cooling system protection at -37°C (-34°F) in order to provide adequate corrosion protection and loss of coolant from boiling.

Adding antifreeze in order to prevent the coolant from boiling too soon is permissible. Too much antifreeze will affect the freezing point. Do not use a solution stronger than 70% antifreeze. A solution stronger than 70% causes the freezing temperature to rise rapidly after this point. Pure antifreeze will freeze at -20°C (-8°F).

Caution: Under pressure, the temperature of the solution in the radiator can be considerably higher, without boiling. Removing the radiator cap while the engine is hot (pressure is high), will cause the solution to boil instantaneously, with explosive force. The solution will spew out over the engine, fenders, and the person removing the cap. Serious bodily injury may result. Flammable antifreeze, such as alcohol, is not recommended for use at any time. Flammable antifreeze could cause a serious fire.

Service the cooling system as follows:

1. Wash the radiator fill cap and the filler neck with clean water.
2. Check the coolant for proper level and freeze protection.
3. Pressure test the system and the radiator fill cap for the proper pressure holding capacity of 103 kPa (15 psi). If replacing the cap, use only a 103 kPa (15 psi) cap.
4. Tighten the hose clamps and inspect all the hoses. Replace any cracked, swollen, or otherwise deteriorated hoses.
5. Clean the frontal area of the radiator core and the air conditioning condenser.
6. Check for proper installation and/or damage to the front air deflector. The front air deflector is located below the front bumper.

This test is done by using a refractometer engine coolant tester. Refractometers test for the amount of glycol in a coolant mixture by measuring the speed of light as light passes through the fluid and is not affected by the specific gravity of the glycol. Refer to Coolant Concentration Testing .

Notice: Do not spray cold water on a hot radiator.

Notice: The heat exchanger fins are necessary for good heat transfer. Do not brush the fins. This may cause damage to the fins, reducing heat transfer.

At least once a year, clean the front face of the radiator. On vehicles with air conditioning, clean the front face of the condenser. Remove any bugs, leaves, and other material by blowing compressed air from the rear of the radiator towards the front of the vehicle. If compressed air is not available, use a water hose to force water through the radiator from the rear toward the front of the vehicle. Use water only with the engine off and cool.

Regular maintenance of the cooling system helps to keep the system operating properly. Check the cooling system at least once a year.

Every five years or 166,000 km (100,000 mi), whichever comes first, drain and refill the cooling system.