Draining and Filling Cooling Systems
Draining and Filling Cooling SystemDraining Procedure
Caution: Refer to Radiator High Pressure Temperature Caution in Service Precautions.
1. Place a drain pan under the radiator drain cock.
2. Place the end of the tube in the drain pan.
3. After the engine cools down, remove the radiator cap or surge tank cap.
4. Using a 1/4 in drive, completely open the radiator drain cock.
5. Allow the coolant to drain from the system until the flow stops.
6. Place a drain pan under the block drain hole plug.
7. Remove the drain hole plug from the engine block.
8. Allow the coolant to drain from the block until the flow stops. There may be more drainage from the radiator at this time.
9. Install the block drain hole plug(s).
Notice: Refer to Fastener Notice in Service Precautions.
10. Apply sealant GM P/N 12346004 or equivalent to all drain plugs.
Tighten the drain plug(s) to 60 Nm (44 ft. lbs.).
11. Close the radiator drain cock.
Filling Procedure
Notice: When adding coolant, use DEX-COOL(R) coolant. If silicated coolant is added to the system, premature engine, heater core or radiator corrosion may result. in addition, the engine coolant will require change sooner-at 50 000 km (30,000 miles) or 24 months.
1. Ensure that the radiator drain cock is closed.
2. Ensure that the block drain hole plug is tight.
3. Add the DEX-COOL to the radiator, then add clean drinkable water to the cooling system. If you use the old coolant, ensure that the solution is clean and clear, and that the solution is a 50/50 mixture of glycol and water.
4. Place a large top funnel in the radiator filler neck or surge tank.
5. Slowly pour in the coolant. Because the thermostat is closed, filling the cooling system may be slow.
6. After you fill the cooling system to 13 mm (0.5 inch) below the radiator filler neck (Gas Engines) or to the full mark on the surge tank (Diesel Engines), start the engine and let the cooling system warm up. When the thermostat opens, the coolant level may drop. If the level drops, add coolant as needed.
7. Install the radiator or surge tank cap.
8. Inspect the coolant level in the coolant recovery reservoir (Gas Engines) or the surge tank (Diesel Engines). Add coolant as needed.