Draining & Refilling the Cooling System

1. Completely drain the system by opening the petcock at the bottom of the radiator, and the plugs in the engine block. If the coolant is dirty, or if there are deposits in the radiator, flush the cooling system before refilling.
2. Remove the radiator cap. Clean, test and replace it, if needed. Clean and inspect the radiator filler neck.

WARNING To avoid the danger of being burned, do not remove the cap while the engine and radiator are still hot. Scalding fluid and steam can be blown out under pressure.

3. Disconnect all hoses from the coolant reservoir. Remove the reservoir and pour out any fluid. Scrub and clean the inside of the reservoir with soap and water. Flush it well with clean water, then drain it. Install the reservoir and hoses.
4. Close the radiator drain cock (and install the block drain plugs if removed).
5. Refill the cooling system with the coolant meeting GM Specifications. To ensure sufficient engine cooling, freezing and corrosion protection, maintain the protection level at -34°F (0°C) or lower. Use a solution that is no more than 70 percent antifreeze.
6. Fill the radiator to the base of the filler neck. Fill the coolant reservoir to the "FULL HOT" mark. Put the reservoir cap back on.
7. Block the drive wheels and firmly apply the parking brake. Shift an automatic transaxle to "P" (park), or a manual transaxle to Neutral. Run the engine, with the radiator cap removed, until the upper radiator hose is hot.
8. With the engine idleing, add coolant to the radiator until it reaches the bottom of the radiator filler neck. Install the radiator cap, making sure the arrows on the cap line up with the overflow tube
a. After servicing the cooling system, an occasional intermittent low coolant light may be encountered during some extreme driving maneuvers. This complaint should be eliminated by 1 or 2 days of normal car operation. Do not operate vehicle if a steady low coolant light is encountered otherwise engine damage will occur.

WARNING Under some conditions, the ethylene glycol in engine coolant is combustible. To help avoid being burned, DO NOT spill antifreeze or coolant on the exhaust system or hot engine parts.

9. Allow the engine to cool to outside temperature, then check the coolant level in the reservoir. If not at the "ADD" (or "FULL COLD") mark, add coolant until it is.
10. Repeat steps 7 through 9 until the level remains at the "ADD" (or "FULL COLD") mark when the engine cools.