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Engine Cooling System: Maintenance Hummer H2 I

Cooling System (Mechanical) ~190 words

Draining and Filling Cooling System

Tools Required

  1. J 26568 Coolant and Battery Tester. See «Special Tools and Equipment»(ref-187257-S03390374262005083100000) .
  2. J 38185 Hose Clamp Pliers. See «Special Tools and Equipment»(ref-187257-S03390374262005083100000) .

Draining Procedure

CAUTIONTo avoid being burned, do not remove the radiator cap or surge tank cap while the engine is hot. The cooling system will release scalding fluid and steam under pressure if radiator cap or surge tank cap is removed while the engine and radiator are still hot.
  1. Follow the steps below in order to remove the surge tank fill cap. Slowly rotate the cap counterclockwise. Stop rotating and allow the hissing to stop. After all the hissing stops, continue turning counterclockwise in order to remove the cap.
  2. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(ref-187252-S32674187102005083100000) in General Information.
  3. Place a drain pan under the lower radiator hose.
  4. Using the J 38185 , reposition the lower radiator hose clamp. See «Special Tools and Equipment»(ref-187257-S03390374262005083100000) .
  5. Remove the lower radiator hose from the radiator.
  6. Drain the cooling system.
  7. If a complete engine block drain is required, remove the left and right engine block coolant drain plugs.
  8. Remove the engine block coolant heater, if equipped. Refer to «Coolant Heater Replacement»(ref-187257-S16516199472005083100000) .
  9. Inspect the coolant.
  10. Follow the appropriate procedure based on the condition of the coolant. Normal in appearance-Follow the filling procedure. Discolored-Follow the flush procedure. Refer to «Flushing»(ref-187257-S39340165612005083100000) .

Flushing

IMPORTANTDo 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 instructions. However, always remove the thermostat before back flushing the system. Block the drive wheels. Place the transmission in park (P) or neutral (N). Engage the park brake. Run the engine until the thermostat opens. Stop the engine. Follow the drain and fill procedure using only clean drinkable water. Repeat the procedure if necessary, until the fluid is nearly colorless. Refer to Draining and Filling Cooling System . Fill the coolant reservoir to the FULL HOT mark. Fill the cooling system. Refer to Draining and Filling Cooling System .

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