Flushing Not Necessary
For vehicles with an electrically-driven A/C compressor, de-energize the high voltage system before removing the A/C compressor. Refer to the appropriate High-Voltage System, De-Energizing service information .
-- Discharge the refrigerant circuit.
-- Remove the A/C compressor.
If a different A/C compressor is installed with a different refrigerant oil, the refrigerant circuit is to be flushed with refrigerant R134a. Refer to REFRIGERANT CIRCUIT, FLUSHING WITH R134A REFRIGERANT .
Electrically-driven A/C compressor:
If an electrically-driven A/C compressor is being replaced that does not have a mechanical fault (for example, a faulty circuit board), then determine how much refrigerant is in this A/C compressor.
This A/C compressor must be flushed to get all the refrigerant oil out.
The A/C compressor is flushed in the flow direction (from the low pressure side input to the high pressure side output)
So that as much refrigerant oil as possible is flushed out of the A/C compressor, the A/C compressor must be positioned so that the high pressure side output is as low as possible.
If an A/C service station without a flushing program is used, the procedure must be performed manually (evacuate, flush 3 times with at least 2 kg refrigerant each and extract refrigerant again, evacuate).
Quantity: for example 50 cm3
Pour so much refrigerant oil out of the new A/C compressor so that only the amount remains (plus 10 cm 3 ) that had been flushed out of the old A/C compressor beforehand. If the new original A/C compressor has for example, 200 cm3 , then only pour out 140 cm3 .
-- Pour old refrigerant oil out of A/C compressor. Handling refrigerant oil.
In not enough refrigerant oil can be poured out from the A/C compressor to be installed, flush the new A/C compressor. After flushing, fill the A/C compressor to be installed with as much new refrigerant oil as was flushed from the replaced A/C compressor.
Mechanically-driven A/C compressor: Draining refrigerant oil via the block connections.
-- To accelerate drainage of refrigerant oil, turn the A/C compressor via the ribbed belt pulley / A/C clutch plate, for example. Does not apply to the electrically-driven A/C compressor.
-- Pour old refrigerant oil out of A/C compressor. Handling refrigerant oil.
-- Only refill with an amount of fresh refrigerant oil that corresponds to the amount poured out (of the faulty A/C compressor).
If, for example, 70 cm3 of refrigerant oil has been poured out of the defective A/C compressor and 220 cm3 out of the replacement A/C compressor (a small quantity of refrigerant oil remains in the A/C compressor). Fill the A/C compressor to be installed with 70 cm3 of refrigerant oil (use can be made of the refrigerant oil poured out of original part A/C compressor).
Use different refrigerant oils and quantities for the various A/C compressors. Refer to AIR CONDITIONING .
If a greater quantity of refrigerant oil (more than approximately 80 cm3 ) has been poured out of the faulty A/C compressor, the remaining refrigerant oil can also be added to the evaporator or reservoir/receiver/dryer. Refer to AIR CONDITIONING .
-- Replace the restrictor depending on the vehicle.
-- Assemble, evacuate and charge the refrigerant circuit.