Cooling System: Service and Repair
DRAINING PROCEDURECAUTION: 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.
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.
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.
10. Close the radiator drain cock.
FILLING PROCEDURE
NOTICE: When adding coolant, use DEX-CO0L 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 mi) 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.
FLUSHING
You can use various methods and equipment to flush the cooling system. If special equipment is used (such as a back flusher) follow the manufacturer's instructions. However, always remove the thermostat before flushing the system.
SCALE REMOVAL
In order to remove hardened scale from the radiator, a direct chemical action is needed.
1. Add a flushing compound, at the specified rate of 30 grams-per-liter (4 ounces-per-gallon) of radiator capacity, to the coolant water as a dissolved solution while the engine is running.
2. Operate the engine for 15 minutes.
3. Drain the cooling system. Then, flush the system with clean drinkable water.
There are various types of flushing compounds commercially available. Obtain these from a reliable source.
Most compounds attack metals and these should not remain in the engine for more than a few minutes. Use a neutralizer in the cooling system immediately after using a de-scaling solvent. For extremely hard, stubborn coatings, such as lime scale, use a stronger solution. The corrosive action of a stronger solution affects the thin metals of the radiator, reducing the operating life of the radiator. Because of this, flushing and rinsing the radiator is required.
After you use the solvent and the neutralizer, and after you flush the system, perform the following steps:
1. Drain the entire cooling system. Refer to Draining and Filling Cooling System.
2. After filling the cooling system, check the radiator and hoses for coolant leaks.