Draining Procedure
| 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. |
Scheme 44
- Place a drain pan under the radiator drain cock.
- After the engine cools down, remove the radiator cap.
- Using a 1/4 inch drive, completely open the radiator drain cock.
- Allow the coolant to drain from the system until the flow stops.
- Place a drain pan under the heater hoses.
- Remove the large heater hose from the heater fitting.
- Allow the coolant to drain from the block until the flow stops. There may be more drainage from the radiator at this time.
- Install the heater hose.
- Close the radiator drain cock.
Flushing
| IMPORTANT | Do not use a chemical flush. Store used coolant in the proper manner, such as in a used engine coolant holding tank. Do not pour used coolant down a drain. Ethylene glycol antifreeze is a very toxic chemical. Do not dispose of coolant into the sewer system or ground water. This is illegal and ecologically unsound. Various methods and equipment can be used to flush the cooling system. If special equipment is used, such as a back flusher, follow the manufacturer's instruction. Always remove the thermostat before flushing the cooling system. |
When the cooling system becomes contaminated, the cooling system should be flushed thoroughly to remove the contaminants before the engine is seriously damaged.
- Drain the cooling system. Refer to «Draining and Filling Cooling System»(ref-191875-S40604209312005091600000) .
- Remove the coolant recovery reservoir. Refer to «Coolant Recovery Reservoir Replacement»(ref-191875-S30873789472005091600000) .
- Clean and flush the coolant recovery reservoir with clean, drinkable water.
- Install the coolant recovery reservoir. Refer to «Coolant Recovery Reservoir Replacement»(ref-191875-S30873789472005091600000) .
- Remove the thermostat. Refer to «Thermostat Replacement (4.2L Engine)»(ref-191875-S40055506622005091600000) .
- Follow the drain and fill procedure using only clean, drinkable water. Refer to «Draining and Filling Cooling System»(ref-191875-S40604209312005091600000) .
- Run the engine for 20 minutes.
- Stop the engine.
- Drain the cooling system. Refer to «Draining and Filling Cooling System»(ref-191875-S40604209312005091600000) .
- Repeat the procedure if necessary, until the fluid is nearly colorless.
- Install the thermostat. Refer to «Thermostat Replacement (4.2L Engine)»(ref-191875-S40055506622005091600000) .
- Fill the cooling system. Refer to «Draining and Filling Cooling System»(ref-191875-S40604209312005091600000) .
