Jeep Wagoneer/Commando/Cherokee 1984-1998

Cooling Systems



See Figures 1 and 2

The cooling system was filled at the factory with a high quality coolant solution that is good for year-round operation, which protects the system from freezing. If coolant is needed, a 50/50 mix of ethylene glycol or other suitable antifreeze and water should be used. Alcohol or methanol base coolants are specifically not recommended. Antifreeze solution should be used all year, even in summer, to prevent rust and to take advantage of the solution's higher boiling point compared to plain water. This is imperative on air conditioned models; the heater core can freeze if it isn't protected.

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Fig. Fig. 1: Be sure the rubber gasket on the radiator cap has a tight seal

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


See Figures 3 and 4

The coolant should be checked at each fuel stop, to prevent the possibility of overheating and serious engine damage. To check the coolant level simply look into the expansion tank.

The radiator coolant is under pressure when hot. To avoid the danger of physical injury, coolant should be checked or replenished only when cool. To remove the cap, slowly rotate it counterclockwise to the stop, but do not press down. Wait until all pressure is released (indicated when the hissing sound stops), then press down on the cap while continuing to rotate it counterclockwise. Wear eye protection and use a glove or a thick rag to prevent burns.

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Fig. Fig. 3: After the engine has cooled, remove the radiator cap to check the coolant level

Never add large quantities of cold coolant to a hot engine. A cracked engine block may result. If it is absolutely necessary to add coolant to a hot engine, do so only with the engine idling and add only small quantities at a time.

If the level is low, simply add coolant mixture to the tank until the upper level line is reached. If the system shows signs of overheating and, possibly, a small leak, you may want to check the level in the radiator when the engine is cold .

Each year, the cooling system should be serviced as follows:

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Fig. Fig. 4: Coolant may be added to the coolant recovery tank or to the radiator

  1. Wash the radiator cap and filler neck with clean water.
  3. Check the coolant for proper level and freeze protection.
  5. Pressure test the cooling system using a cooling system pressure tester and follow the tool manufacturers instructions. If a replacement cap is installed, be sure that it conforms to the original specifications.
  7. Tighten the hose clamps and inspect all hoses. Replace hoses that are swollen, cracked or otherwise deteriorated.
  9. Clean the frontal area of the radiator core, and the air conditioning condenser, if so equipped.


See Figures 5, 6 and 7

Never open, service or drain the radiator or cooling system when hot; serious burns can occur from the steam and hot coolant. Also, 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 quantities. Always drain coolant into a sealable container. Coolant should be reused unless it is contaminated or is several years old.

Every 3 years or 45,000 miles (72,000 km) whichever comes first, the system should be serviced as follows:

  1. On Cherokee, Comanche and Wagoneer models, remove the front grille assembly.
  3. With the engine turned off and sufficiently cooled down, remove the radiator cap.

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Fig. Fig. 5: Location of the radiator draincock behind the front grille on Wagoneer, Cherokee and Comanche models

  1. Place a drain pan underneath the radiator, then open the draincock which is found in the following locations:

    4- and 6-cylinder engines-right, lower side of the radiator
    V-8 engines-left, lower side of the radiator facing the rear of the vehicle


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Fig. Fig. 6: Location of the cylinder block drain plug-6-cylinder engine

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Fig. Fig. 7: Location of the cylinder block drain plugs-V-8 engines

  1. If necessary, remove the cylinder block drain p