Regular maintenance will keep the cooling system operating properly. Use the following procedures in order to check the cooling system at least once a year or 25000 km (15000 miles).

Long Life Engine Coolant

DEX-COOL™ engine coolant is a long life engine coolant and is ethylene glycol based, silicate- free and orange in color. DEX-COOL™ coolant provides longer lasting protection against rust and corrosion, and increases water pump seal life. DEX-COOL™ will give freezing protection down to -34°F (-37°C) and boiling protection up to 265°F (129°C). This coolant meets GM Specification 6277M.

Checking Engine Coolant

Check the engine coolant level in the reservoir by removing the reservoir cap and checking the dipstick with the engine cold. The level should be at or above the FULL COLD mark on the dipstick. At normal operating temperature, the engine coolant level should be at or above the FULL HOT mark on the dipstick.

Add engine coolant only to the reservoir in order to raise the level to the appropriate mark. Use a 50/50 mixture of DEX-COOL™ engine coolant and water (preferably distilled) for engine coolant additions. Every five years or 241 - 350  kilometers (150,000  miles), whichever comes first, drain and refill the cooling system. Refer to Cooling System Draining and Filling .

Engine Coolant Concentration

The percentage of ethylene glycol in the engine coolant should be checked periodically, when the engine coolant level is adjusted or the system is drained and refilled. This test is done by using a refractometer. Refractometers test for the amount of ethylene glycol in the coolant mixture by measuring the speed of light as it passes through the fluid and is affected by the specific gravity of the glycol. Refer to Coolant Concentration Testing .

Hose and Clamp Inspection

Inspect the condition of all the hoses and clamps. Hoses should be flexible and show no signs of bulging, cracks, kinks, or other signs of possible leakage. Inspect the clamps and tighten as necessary.

Pressure Testing

Test the radiator fill cap for the proper pressure holding capacity. Refer to Radiator Cap . For cooling system pressure testing, refer to Radiator Leak Testing .

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

Important: The radiator fins are necessary for good heat transfer and should not be brushed. Brushing may damage the fins, which would reduce the heat transfer.

Exterior Radiator Cleaning

Clear away bugs, leaves, and other debris from the small air passageways of the radiator. This will improve the operation of the cooling system. Use compressed air to blow through the radiator from the rear towards the front of the vehicle. If compressed air is not available, water can be used by directing the water hose from the rear of the radiator.