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Refrigerant circuit, function - GF83.40-P-2001B

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MODEL 140 as of 1.9.95 

Fig 1: Refrigerant Circuit Function Diagram
G05440708Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

The A/C compressor (1) is driven by the engine and compresses the gaseous refrigerant which heats up, flows to the condenser (2) where it is cooled down. The heat from compression is removed from the refrigerant by the surface of the condenser (2). As it cools the refrigerant liquefies.

As it flows through the receiver/drier (3) the refrigerant is purified of all chemical and mechanical impurities.

The liquid refrigerant then flows through the expansion valve (4) into the evaporator (5), located in the fresh air flow. The refrigerant evaporates here. The evaporation process absorbs heat from the fresh air flowing by on the outside of the system of tubes and honeycombs so that they cool the fresh air.

On vehicles with rear air conditioning  the liquid refrigerant flows from the receiver/drier (3) through the refrigerant injection valve (8) and the refrigerant shutoff valve (7) into the rear air conditioning evaporator (6).

The moisture contained in the air is condensed out and the water condensate is drained to the outside. The air is dried.

The A/C compressor (1) sucks in the refrigerant which has now become gaseous due to the heat it has absorbed and compresses it again.

When the engine is running and the blower is switched on cool air can be let into the interior via various outlets. The intensity of the refrigeration depends on the interior temperature and blower speed set previously.

  Auxiliary fan, location/purpose/function   GF83.40-P-2162A 
  Auxiliary fan control module, location/purpose/function   GF83.40-P-2163A 
  Condenser, location/purpose/function   GF83.40-P-2152A 
  Evaporator, location/purpose/function   GF83.40-P-2164A 
  Rear air conditioning evaporator, location/purpose/function with code 582 (rear air conditioning) GF83.50-P-2111S 
  Receiver, location/purpose/function   GF83.40-P-2153A 
  Expansion valve, location/purpose/design/function   GF83.40-P-2123A 
  Rear air conditioning refrigerant shutoff valve, location/purpose/function with code 582 (rear air conditioning) GF83.50-P-2103S 
  Refrigerant injection valve, location/purpose with code 582 (rear air conditioning) GF83.50-P-2118S 
  Refrigerant temperature sensor, location/purpose/function   GF83.40-P-2154A 
  Air conditioning coolant temperature sensor, location/purpose/function   GF83.40-P-2155A 
  Refrigerant pressure sensor, location/purpose/function   GF83.40-P-2156A 
  A/C compressor, location/purpose/design/function Engines 104, 119 GF83.55-P-2100A 
    Engine 120 GF83.55-P-2100B 
  Electromagnetic clutch, location/purpose/design/function   GF83.55-P-2101A 
  Evaporator temperature sensor, location/purpose/function   GF83.57-P-2109A 
    with code 582 (rear air conditioning) GF83.57-P-2109S