Jeep Wagoneer/Commando/Cherokee 1957-1983 Repair Information

Coolant

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CAUTION
When draining engine coolant, keep in mind that cats and dogs are attracted to ethylene glycol antifreeze and could drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain coolant into a sealable container. Coolant should be reused unless it is contaminated or is several years old.

COOLANT CHECK AND CHANGE



See Figures 1, 2 and 3

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Fig. Fig. 2: Periodically remove all debris from the radiator fins



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Fig. Fig. 3: Cooling systems should be pressure tested for leaks periodically



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Fig. Fig. 4: Cutaway view of a typical cooling system flow

On systems without a coolant recovery tank, the engine coolant level should be maintained 1-2 in. below the bottom of the radiator filler neck when the engine is at air temperature and 1 in. below the bottom of the filler neck when the engine is hot.

On systems with a coolant recovery tank, maintain the coolant level at the level marks on the recovery bottle.

For best protection against freezing and overheating, maintain an approximate 50% water and 50% ethylene glycol antifreeze mixture in the cooling system. Do not mix different brands of antifreeze to avoid possible chemical damage to the cooling system.

Avoid using water that is known to have a high alkaline content or is very hard, except in emergency situations. Drain and flush the cooling system as soon as possible after using such water.


CAUTION
Cover the radiator cap with a thick cloth before removing it from a radiator in a vehicle that is hot. Turn the cap counterclockwise slowly until pressure can be heard escaping. Allow all pressure to escape from the radiator before completely removing the radiator cap. It is best to allow the engine to cool if possible, before removing the radiator cap.

Never add cold water to an overheated engine while the engine is not running.

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.

DRAINING, FLUSHING AND REFILLING



See Figures 1 through 5

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Fig. Fig. 1: Open the radiator petcock and drain the coolant into a suitable container



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Fig. Fig. 2: When draining the cooling system make sure the coolant has cooled sufficiently before removing the radiator cap



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Fig. Fig. 3: When refilling the system, add the proper amount of coolant to the radiator using a funnel to avoid spilling



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Fig. Fig. 4: When topping off the system add the coolant through the coolant recovery/overflow tank



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Fig. Fig. 5: Be sure the rubber gasket on the radiator cap has a tight seal

To drain the cooling system, allow the engine to cool down before attempting to remove the radiator cap. Then turn the cap until it hisses. Wait until all pressure is off the cap before removing it completely.


CAUTION
To avoid burns and scalding, always handle a warm radiator cap with a heavy rag.


CAUTION
When draining engine coolant, keep in mind that cats and dogs are attracted to ethylene glycol antifreeze and could drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain coolant into a sealable container. Coolant should be reused unless it is contaminated or is several years old.

  1. At the dash, set the heater temp control lever to the fully HOT position.
  2.  
  3. With the radiator cap removed, drain the radiator by loosening the petcock at the bottom of the radiator. Locate any drain plugs in the block and remove them. Flush the radiator with water until the fluid runs clear.
  4.  
  5. Close the petcock and replace the plug(s), then refill the system with a 50/50 mix of ethylene glycol antifreeze. Fill the system to 3 / 4 -1 1 / 4 in. from the bottom of the filler neck. Reinstall the radiator cap.
  6.  

If equipped with a fluid reservoir tank, fill it up to the MAX level.

  1. Operate the engine at 2,000 rpm for a few minutes and check the system for signs of leaks.
  2.  

RADIATOR CAP INSPECTION



Allow the engine to cool sufficiently before attempting to remove the radiator cap. Use a rag to cover the cap, then remove by pressing down and turning counterclockwise to the first stop. If any hissing is noted (indicating the release of pressure), wait until the hissing stops completely, then press down again and turn counterclockwise until the cap can be removed.


CAUTION
DO NOT attempt to remove the radiator cap while the engine is hot. Severe personal injury from steam burns can result.

Check the condition of the radiator cap gasket and seal inside of the cap. The radiator cap is designed to seal the cooling system under normal operating conditions which allows the build up of a certain amount of pressure (this pressure rating is stamped or printed on the cap). The pressure in the system raises the boiling point of the coolant to help prevent overheating. If the radiator cap does not seal, the boiling point of the coolant is lowered and overheating will occur. If the cap must be replaced, purchase the new cap according to the pressure rating which is specified for your vehicle.

Prior to installing the radiator cap, inspect and clean the filler neck. If you are reusing the old cap, clean it thoroughly with clear water. After turning the cap on, make sure the arrows align with the overflow hose.

 
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