Heating and Air Conditioning...Title Heating and Air Conditioning Author Mario Created Date 4/1/2020...

Copyright © 2014 Delmar, Cengage Learning

Heating and Air Conditioning

Chapter 26


Cooling System Components

• Water pump–Used to circulate

coolant through the engine and cooling system

–Usually driven by the timing belt or accessory drive belts



• Radiator

– Transfers the heat retained in the coolant to the outside air



• Radiator fan

–May be belt driven, electric, or hydraulic

–Used to pull air through the radiator when vehicle speeds are low



• Thermostat

–Usually located in the intake manifold

–Prevents coolant flow from the engine to the radiator until the coolant temperature reaches a certain point


Example of a Cooling System


Thermostats

Click on image above to play video

coolingThermostat.mp4

coolingThermostat.mp4


Fan Clutch


Electric Fan


Mode Controls and Air Flow


Blower Circuit


Refrigerant System Components

• Refrigerant

–All vehicles since 1995 have been equipped with R-134a

–Manufacturers are expected to introduce new refrigerant in future years



• Compressor

– Separates the low and high pressure sides of the system



• Accumulator is placed on the low side of the system after the evaporator and before the compressor

– Used to trap liquid refrigerant before it can enter the compressor



• Receiver dryer is placed in the high pressure side of the system between the condenser and the expansion valve

– Used to store refrigerant until it is needed by the system



• Evaporator

– Transfers the heat in the passenger compartment to the refrigerant



• Condenser

– Transfers heat from the refrigerant to the outside air



• Orifice tube/expansion valve

– Restriction designed to drop refrigerant pressure before it enters the evaporator


Refrigerant System Schematic


Heat Exchange


Air Conditioning Safety

• Always wear safety glasses or goggles

• Never open a hot cooling system

• Keep loose clothing and jewelry away from moving components


Air Conditioning Safety

• Never open the A/C system unless the refrigerant has been reclaimed from the system

• Do not attempt to open, disconnect, or service any high-voltage component or wiring


Coolant Label


Coolant System Testing

Click on image above to play video

coolingPressure.mp4

coolingPressure.mp4


Cooling System Pressure Test

• With the engine cool, remove the radiator cap

• Attach the proper adapter to the filler neck



• Apply pressure to the cooling system

–DO NOT exceed the pressure shown on the cap



• Watch the pressure on the gauge

–If the pressure remains steady, there is not a large leak

• With pressure on the system, check the system for leaks


Cap Test


Refractometer Test


Cabin Filter Replacement

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Heating and Air Conditioning...Title Heating and Air Conditioning Author Mario Created Date 4/1/2020...

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