Honda Accord/Civic/Prelude 1973-1983 Repair Guide



See Figures 1 and 2

On 1170cc and 1237cc vehicles, the thermostat is located on the intake manifold, under the air cleaner nozzle, so you will first have to remove the air cleaner housing. On the CVCC and late model engines, it is located at the right rear of the distributor housing.


  1. Place a clean drain pan under the radiator, remove the drain plug from the radiator and drain the coolant into the pan.

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. Remove the thermostat cover-to-thermostat housing bolts, the cover, the gasket and the thermostat.

Click image to see an enlarged view

Fig. Fig. 1: Exploded view of the thermostat housing-Civic models

Click image to see an enlarged view

Fig. Fig. 2: View of removing the thermostat and housing-note radiator hose still connected to housing

  1. Using a putty knife, clean the gasket mounting surfaces.

If the thermostat is equipped with a pin valve, be sure to install the thermostat with the pin facing upward.

  1. To install, use a new thermostat (if necessary), gasket, O-ring (if used), sealant (if necessary) and reverse the removal procedures. Always install the spring end of the thermostat facing the engine. Torque the thermostat cover-to-thermostat housing bolts to 7 ft. lbs. (1973-78) or 9 ft. lbs. (1979-83). Bleed the cooling system.