Cooling, heating and air conditioning systems Ford F150
Engine cooling system
1. The cooling system consists of a radiator, an expansion tank, a pressure cap (located on the expansion tank), a single thermostat, cooling fans and a belt-driven water pump.
2. The expansion tank (referred to by the manufacturer as a «degas bottle») functions somewhat differently than a conventional recovery tank. Designed to separate any trapped air in the coolant, it is pressurized by the radiator and has a pressure cap on top. The radiator on these models does not have a pressure cap. When the thermostat is closed, no coolant flows in the expansion tank, but when the engine is fully warmed up, coolant flows from the top of the radiator through a small hose that enters the top of the expansion tank, where the air separates and the coolant falls into a coolant reservoir in the bottom of the tank, which is fed to the cooling system through a larger hose connected to the lower radiator hose.
Warning: Unlike a conventional coolant recovery tank, the pressure cap on the expansion tank should never be opened after the engine has warmed up, because of the danger of severe burns caused by steam or scalding coolant.
3. Coolant in the left side of the radiator circulates through the lower radiator hose to the water pump, where it is forced through coolant passages in the cylinder block. The coolant then travels up into the cylinder head, circulates around the combustion chambers and valve seats, travels out of the cylinder head past the open thermostat into the upper radiator hose and back into the radiator.
4. When the engine is cold, the thermostat restricts the circulation of coolant to the engine. When the minimum operating temperature is reached, the thermostat begins to open, allowing coolant to return to the radiator.
Transmission cooling systems
5. Vehicles with an automatic transmission are equipped with a external transmission cooler. The cooler is located in front of the radiator and is connected to the cooler by two hoses: one delivers hot transmission fluid to the radiator and the other brings the cooled fluid back to the transmission.
Engine oil cooling system
6. Besides the engine and transmission cooling systems described above, engine heat is also dissipated through an external oil cooler that’s integrated into the lubrication system. The oil cooler helps keep engine oil temperatures within design limits under extreme load conditions.
7. The oil cooling system consists of a cooler housing mounted between the oil filter
and the filter adapter (3.5L V6 and V8 models) or a cooler mounted on the front cover at the front of the right cylinder head (2.7L V6 models) and a pair of hoses that circulate coolant through the cooler.
Heating system
8. The heating system consists of the heater controls, the heater core, the heater blower assembly (which houses the blower motor and the blower motor resistor), and the hoses connecting the heater core to the engine cooling system. Hot engine coolant is circulated through the heater core. When the heater mode is activated, a flap door opens to expose the heater box to the passenger compartment. A fan switch on the heater controls activates the blower motor, which forces air through the core, heating the air.
Air conditioning system
9. The air conditioning system consists of the condenser, which is mounted in front of the radiator, the evaporator case assembly under the dash, a compressor mounted on the engine, and the plumbing connecting all of the above components.
10. A blower fan forces the warmer air of the passenger compartment through the evaporator core (sort of a radiator-in-reverse), transferring the heat from the air to the refrigerant. The liquid refrigerant boils off into low pressure vapor, taking the heat with it when it leaves the evaporator.
Troubleshooting
Air conditioning and heating system – check and maintenance
Thermostat – replacement
Expansion tank – removal and installation
Cooling fan and shroud – removal and installation
Radiator – removal and installation
Cooling module – removal and installation
Water pump – removal and installation
Coolant temperature sending unit – general information
Air conditioning and heater blower/control module – replacement
Heater core – removal and installation
Interior cabin heater coolant pump – removal and installation
Air conditioning and heater control module – removal and installation
Air conditioning receiver-drier (desiccant bag) – removal and installation
Air conditioning compressor – removal and installation
Air conditioning condenser – removal and installation
Air conditioning evaporator core – removal and installation
Air conditioning pressure cycling switch replacement
Air conditioning thermostatic expansion valve (TXV) – general information
Oil cooler – removal and installation
Block heater – replacement