Ford Mustang/Capri 1979-1988 Repair Guide



On models equipped with an electric cooling fan, disconnect the negative battery cable, or fan motor wiring harness connector before replacing any radiator/heater hose. The fan may come on, under certain circumstances, even though the ignition is Off.


Inspect the condition of the radiator and heater hoses periodically. Early spring and at the beginning of the fall or winter, when you are performing other maintenance, are good times. Make sure the engine and cooling system are cold. Visually inspect for cracking, rotting or collapsed hoses, and replace as necessary. Run your hand along the length of the hose. If a weak or swollen spot is noted when squeezing the hose wall, replace the hose.


See Figures 1 and 2

  1. Loosen the radiator cap and open the petcock, if equipped. Drain the cooling system into a suitable container at least to a level below that of the hose to be replaced. Since coolant is also hazardous to the environment, it should never be poured into drains, sewers or water supplies. Recycle old or contaminated coolant. Many garages and auto parts stores offer free disposal of used coolant to their customers.

When draining the coolant, keep in mind that cats and dogs are attracted by the 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.

  1. Loosen the hose clamps at each end of the hose that requires replacement.
  3. Carefully twist, pull and slide the hose off the radiator, water pump, thermostat housing or heater core fitting. If you encounter resistance from an old hose which is not reusable, you may slit the hose lengthwise at the end just enough to peel it back. Be careful not to exert too much force on delicate metal fittings.

To install:
  1. If a new hose is to be installed, verify that it is the same length and shape as the one removed.
  3. Clean the fittings and coat them with a water resistant sealer. Position new hose clamps on the hose.
  5. Slide the hose into position, making sure the hose clamps are located beyond the raised bead of the fitting, if equipped, and centered in the clamping area.
  7. Tighten the clamps to 20-30 inch lbs. Do not overtighten.
  9. Refill the cooling system to the normal level. If new coolant is added, it may be mixed with water to the desired concentration.
  11. Start the engine and allow it to reach normal operating temperature. Check for leaks.

Click image to see an enlarged view

Fig. Fig. 1: Loosening a radiator hose clamp

Click image to see an enlarged view

Fig. Fig. 2: Loosening a heater hose clamp