Ford Full-Size Cars 1968-1988 Repair Guide




See Figures 1, 2, 3, 4 and 5

When draining 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 the coolant into a sealable container. Coolant should be reused unless it is contaminated or several years old.

  1. Raise and support the vehicle safely on jackstands.
  3. From the driver's side portion of the radiator, open the draincock and drain the radiator so the coolant level is below the coolant outlet elbow which houses the thermostat. If the radiator has been replaced, the replacement unit may not have a draincock. In this case the lower radiator hose will have to be loosened and removed to allow for the coolant to drain out.

On some models it may be necessary to remove the distributor in order to gain access to the thermostat housing mounting bolts.

  1. Remove the outlet elbow retaining bolts and position the elbow clear of the intake manifold or cylinder head to provide access to the thermostat.

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Fig. Fig. 1: Loosen and remove the bolts and/or stud which secure the thermostat housing to the engine

Remember the direction the thermostat was facing when removed to ensure that it is installed in the correct manner

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Fig. Fig. 2: Make a note of the thermostat positioning in its housing

  1. Remove the thermostat and the gasket. Clean any gasket material from both mating surfaces. Always replace the gasket.

To install:
  1. Coat the new gasket with water resistant sealer. Install the thermostat in the block on the 5.8L and 6.6L engines, then install the gasket. On all other engines, position the gasket on the engine, and install the thermostat in the coolant elbow.
  3. Install the outlet elbow then the retaining bolts on the engine. Tighten the bolts evenly in steps to 12-15 ft. lbs. (16-20 Nm).
  5. Refill the radiator and overflow tank, if equipped.
  7. Lower the vehicle. Start the engine and bleed the cooling system, if necessary. Refer to the service procedure below. Recheck the coolant level.

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Fig. Fig. 3: 6 cylinder thermostat assembly

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Fig. Fig. 4: Thermostat assembly used on some 8 cylinder engines

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Fig. Fig. 5: Thermostat design