Honda Accord/Civic/Prelude 1973-1983 Repair Guide



The Honda employs water-cooling for engine heat dissipation. Air is forced through the radiator by an electric fan which is, in turn, activated by a water temperature sensor screwed into the base of the radiator.

DO NOT attempt to open the cooling system when the engine is Hot; the system will be under high pressure and scalding may occur.


See Figures 1 through 5

When removing the radiator, take care not to damage the core and fins.

  1. Position a clean drain pan under the radiator, open the drain plug, remove the radiator cap and drain the cooling system.

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. Disconnect the electrical connectors from the thermo-switch and the cooling fan motor.

Click image to see an enlarged view

Fig. Fig. 1: Removing the radiator mounting bolts

Click image to see an enlarged view

Fig. Fig. 2: Removing the radiator upper hose

Click image to see an enlarged view

Fig. Fig. 3: Removing the transaxle oil cooler from the radiator

Click image to see an enlarged view

Fig. Fig. 4: Removing the radiator with cooling fan attached

Click image to see an enlarged view

Fig. Fig. 5: View of the electrical connectors for the radiator thermo-switch

  1. Disconnect the upper coolant hose at the upper radiator tank and the lower hose at the water pump connecting pipe. Disconnect the overflow hose from the coolant tank.
  3. Remove the turn signals (Civic 1973-77) and front grille.
  5. Remove the radiator-to-chassis bolts and the radiator with the fan attached. The fan can be easily unbolted from the back of the radiator.
  7. Inspect the hoses for damage, leaks and/or deterioration; if necessary, replace them. If the radiator fins are clogged, wash off any insects or dirt with low pressure water.
  9. To install, use new O-rings (if used) and reverse the removal procedure. Torque the radiator-to-chassis bolts to 7 ft. lbs. Refill and bleed the cooling system; if equipped with a coolant reservoir, be sure to fill it to proper level. Start the engine, allow it to reach normal operating temperatures and check for leaks.