Peugeot 406

since 1996 release

Repair and operation of the car

Peugeot 406
+ 1. Maintenance instruction
+ 2. Maintenance
+ 3. Engine
- 4. Cooling systems, heating and ventilation
   4.1. Technical data
   4.2. Connection of hoses of the cooling system
   4.3. Radiator
   4.4. Thermostat
   4.5. Electric fan
   4.6. Thermal sensors
   4.7. Sensor of a lamp of excess of temperature of cooling liquid
   4.8. Water pump
   4.9. Heating system and ventilation
   4.10. Elements of system of heating
   4.11. Air conditioning systems
+ 5. Fuel system
+ 6. System of ignition
+ 7. Coupling
+ 8. Transmissions
+ 9. Power shafts
+ 10. Brake system
+ 11. Suspension bracket and steering
+ 12. Body
+ 13. Electric equipment
+ 14. Main malfunctions

4. Cooling systems, heating


The cooling system of the closed tight type turns on the water pump which is given by a gear belt, an aluminum radiator, the electric fan of a radiator, the thermostat, a heater, hoses and switches.

The system functions as follows. Cold cooling liquid from the lower part of a radiator arrives on a hose to the water pump and is pumped over via the main channels of the block of cylinders of the engine, and also via the oil heater (where is available). After cooling of cylinders of the engine, the combustion chamber and saddles of valves, cooling liquid moves to the thermostat which during an initial stage of time is closed. Cooling liquid also passes through a heater and comes back via the block of cylinders to the water pump.

On the cold engine cooling liquid circulates only via the block of cylinders, a head of the block of cylinders and a heater. At achievement by cooling liquid of a certain temperature the thermostat begins to open and cooling liquid arrives through the top hose to a radiator. As cooling liquid begins to circulate, there is its cooling with an air stream at the movement of the car. If necessary the stream of air increases during the operation of the electric fan(s). After achievement of the basis of a radiator cooling liquid was cooled, and the cycle will be repeated.

When the engine is heated-up up to the normal working temperature, cooling liquid extends and forced out in a broad tank. When cooling the engine the cooling system is fed from a broad tank.

On cars with the automatic transmission a part of cooling liquid arrives from the radiator basis via the refrigerator installed on the transmission. On the cars having the oil heater, cooling liquid also passes through it.

The electric fan of a radiator is run by the thermal sensor which at excess of a certain temperature of cooling liquid turns on the fan.


When opening a cover of a broad tank on the hot engine it is necessary to be careful since the coming-out hot vapors and cooling liquid can lead to severe burns. Do not allow hit of cooling liquid on clothes and a paint and varnish covering of a body. Otherwise wash out a surface a plentiful amount of water.

At depressurization of the cooling system at the hot engine place fabric on a cover of a jellied mouth on a broad tank, slowly unscrew a cover to dump pressure. When all pressure in the cooling system is dumped, uncover a jellied mouth.