Mitsubishi Eclipse 1990-1998 Repair Guide

Cooling System

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See Figure 1


CAUTION
When draining the coolant, keep in mind that cats and dogs are attracted by ethylene glycol antifreeze, and are quite likely to drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain the coolant into a sealable container. Coolant should be reused unless it is contaminated or several years old (in which case it should be taken to a recycling facility such as a service station).



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Fig. Fig. 1: Cutaway view of a typical cooling system flow

FLUID RECOMMENDATIONS



The cooling fluid or antifreeze normally should be changed every 30,000 miles (48,000 km) or 24 months. When replacing the fluid, use a mixture of 50% water and 50% ethylene glycol antifreeze.

LEVEL CHECK



See Figures 2, 3 and 4

Check the coolant level every 3,000 miles or once a month. In hot weather operation, it may be a good idea to check the level once a week. Check for loose connections and signs of deterioration of the coolant hoses. Check the coolant level in the reservoir when the engine is cold, making sure the level is at the FULL or MAX mark. If the bottle is empty, check the level in the radiator and refill as necessary. Then fill the bottle up to the FULL or MAX level.



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Fig. Fig. 2: The coolant reservoir has FULL (A) and LOW (B) marks located on the tank



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Fig. Fig. 3: Be EXTREMELY careful when working around the electric cooling fan


CAUTION
Never remove the radiator cap when the vehicle is hot or overheated. Wait until it has cooled. Place a thick cloth over the radiator cap to shield yourself from the heat and turn the radiator cap, SLIGHTLY, until the sound of escaping pressure can be heard. DO NOT turn any more; allow the pressure to release gradually. When no more pressure can be heard escaping, remove the cap with the heavy cloth, CAUTIOUSLY.

Never add cold water to an overheated engine.

After filling the radiator, run the engine until it reaches normal operating temperature, to make sure that the thermostat has opened and all the air is bled from the system.



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Fig. Fig. 4: Add the proper water/coolant mixture to the reservoir until the fluid reaches the proper level

DRAIN & REFILL



See Figures 5, 6, 7, 8, 9, 10 and 11


CAUTION
Do not remove a radiator cap while the engine and radiator are still hot. Danger of burns by scalding fluid and steam under pressure may result!

  1. Make sure the vehicle is parked on a level surface.
  2.  
  3. Remove the coolant recovery reservoir fill cap.
  4.  
  5. With a cool engine, slowly rotate the radiator cap counterclockwise to the detent without pressing down on the cap.
  6.  
  7. Wait until any remaining pressure is relieved by listening for a hissing sound.
  8.  
  9. After all the pressure is relieved, press down on the cap and continue to rotate the radiator cap counterclockwise.
  10.  



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Fig. Fig. 5: NEVER remove the radiator cap when the engine is hot!

  1. With a suitable container to catch the fluid under the radiator, open the radiator drain cock.
  2.  



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Fig. Fig. 6: The radiator drain cock is located at the bottom corner of the radiator

  1. If equipped, remove the engine block drain plugs. This will help to drain the coolant from the block.
  2.  



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Fig. Fig. 7: If equipped, remove the engine block drain plugs and let the coolant drain into a suitable container

  1. Loosen or slide the recovery tank hose clamp at the radiator filler neck overflow tube and remove the hose. Holding the hose down to the drain pan, allow the recovery tank to empty. Attach the hose to the filler neck overflow and tighten the clamp.
  2.  
  3. Close the radiator drain cock and install the engine block drain plug.
  4.  
  5. Add enough coolant mixture to fill the system to a level just below the radiator neck. Fill the reservoir assembly to the FULL mark.
  6.  

Fill the cooling system with a 50/50 mixture of water and Ethylene Glycol antifreeze.



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Fig. Fig. 8: Refill the system by adding coolant through the radiator filler neck

  1. Firmly set the parking brake. Run the engine with the radiator cap OFF, until normal operating temperature is reached.
  2.  


CAUTION
Under some conditions, ethylene glycol is flammable. To avoid being burned when adding engine coolant, do not spill it on the exhaust system or on hot engine parts.

  1. With the engine idling, add engine coolant to the radiator until the level reaches the bottom of the radiator fill neck. Install the cap assembly.
  2.  



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Fig. Fig. 9: Cooling systems should be pressure tested for leaks periodically



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Fig. Fig. 10: Be sure the rubber gasket on the radiator cap has a tight seal



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Fig. Fig. 11: Periodically remove all debris from the radiator fins

Never add cold water to an overheated engine.

  1. Add coolant to the recovery tank, as necessary.
  2.  
  3. After filling the radiator and recovery tank, run the engine until it reaches normal operating temperature, to make sure that the thermostat has opened and all the air is bled from the system.
  4.  

FLUSHING & CLEANING THE SYSTEM



  1. Drain the cooling system. Close the petcock slightly.
  2.  
  3. Remove the thermostat from the engine. Disconnect the upper radiator hose at the radiator neck.
  4.  
  5. Install a high pressure hose into the thermostat housing and allow the water pressure to back-flush the system.
  6.  
  7. Continue this procedure until the water coming from the hose is clean.
  8.  
  9. Reverse the removal procedure and refill the cooling system with fresh coolant.
  10.  

 
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