Refrigerant Circuit, Flushing With R134A Refrigerant

The Refrigerant Circuit Should Be Flushed With Refrigerant R134a 

• there is dirt or other contamination in the refrigerant circuit.
• vacuum reading is not maintained when evacuating a leak-free refrigerant circuit (pressure build-up due to moisture in refrigerant circuit).
• the refrigerant circuit has been left open for longer than normal (for example, after a collision).
• If pressure and temperature measurements in the refrigerant circuit indicate the likelihood of moisture in the refrigerant circuit.
• It is not clear how much refrigerant oil is in the refrigerant circuit. If the A/C compressor should be reinstalled, the refrigerant oil should be drained from the A/C compressor via the block connections if this is the case. To facilitate this, the ribbed belt pulley or A/C clutch plate on the A/C compressor should be rotated by hand. After flushing, the entire quantity of refrigerant oil specified by the Vehicle-Specific Service Information must be added to the refrigerant circuit (50 grams directly into the A/C compressor). Note additional oil quantity for systems with a second evaporator.
• A/C compressor had to be replaced due to internal damage (for example, noise or no output).
• It is stipulated by the vehicle-specific Service Information following the replacement of certain components.
• Another A/C compressor with a different refrigerant oil should be installed.