Refrigerant Circuit, Cleaning With Compressed Air

WARNING: This page is about a different car, the 2022 Volkswagen ID.4 and 2021 Volkswagen ID.4. However, it is still accessible from the selected car via links, so may be relevant.

If there are components that have no suitable connecting adapters from the VW/Audi - Passenger Vehicle Adapter Set, use, for example, an air blow gun with a rubber mouth piece for cleaning the individual components. When using an air blow gun with a rubber mouthpiece, take special care not to damage the connections (bending or scratching).
Always blow through components in the opposite direction of refrigerant flow (or flush with refrigerant R1234yf or R134a).
Check the expansion valve and replace if dirty or corroded.
Locate any components with dark, sticky deposits on them that cannot be removed with compressed air, and either flush this refrigerant circuit with refrigerant R1234yf or R134a, or replace them.
Thin, light gray deposits on the inside (of pipes) do not impair the function of the components.
After blowing through, replace the accumulator (with desiccant bag) and the expansion valve. Replace the desiccant bag on gas coolers that have a desiccant bag installed in the integrated receiver/dryer.
Gas coolers, which have an integrated receiver/dryer / desiccant bags that cannot be replaced separately or are not available as a replacement part, must be replaced after flushing the refrigerant circuit. Refer to the Parts Information and Refrigerant Circuit (vehicle-specific Service Information).

The circuit (or individual components) must be blown through (if there is no possibility for flushing or flushing is not recommended):

-- In the event dirt or other contaminants are located in individual components of the circuit.

-- If the vacuum reading does not stay the same when evacuating a leak-free refrigerant circuit (pressure build-up due to moisture in the refrigerant circuit).

-- The refrigerant circuit has been left open for longer than normal (for example, after a collision).

-- Pressure and temperature measurements in the circuit indicate that there is moisture in the refrigerant circuit.

-- It is stipulated in the vehicle-specific Service Information following the replacement of certain components. Refer to Refrigerant Circuit .

Refrigerant Circuit, Cleaning with Compressed Air

Use an extraction unit to extract the mixture of refrigerant, refrigerant oil and compressed air that is coming from the components.
Always clean components in the opposite direction of refrigerant flow (flushing with refrigerant R1234yf or R134a) or blow through.
The compressed air must be routed through a compressed air cleaning device for cleaning and drying. For this reason use the filter and dryer for the compressed air (included in delivery package as a tool for paint work). Refer to the Parts Information.
To blow through components, use adapters from the VW/Audi - Passenger Vehicle Adapter Set or commercially available air blow guns with a rubber mouth piece.

-- First use compressed air to blow out any old refrigerant oil and dirt.

After blowing through the refrigerant circuit:

-- Replace these vehicle-specific components (accumulator, expansion valve and receiver/dryer and/or desiccant bag). Refer to Refrigerant Circuit (vehicle-specific Service Information) and the Parts Information.

-- Depending on the complaint, replace the expansion valve. Refer to Refrigerant Circuit (vehicle-specific Service Information).

-- Depending on the concern, replace the A/C compressor. Refer to Refrigerant Circuit (vehicle-specific Service Information) and the Parts Information), or let the remaining refrigerant oil flow out of the removed A/C compressor (refer to COMPONENTS, REPLACING ) and refill the specified quantity of fresh refrigerant oil. Refer to Technical Data (vehicle-specific Service Information) and REFRIGERANT OIL CAPACITIES, R1234YF (vehicle-specific Service Information).

-- Completely reassemble the refrigerant circuit. Refer to Refrigerant Circuit (vehicle-specific Service Information).

-- Evacuate and fill the refrigerant circuit according to the procedure. Refer to REFRIGERANT CIRCUIT, EVACUATING and Refer to REFRIGERANT CIRCUIT, CHARGING .

-- Start up the A/C system according to the specifications. Refer to Refrigerant Circuit (vehicle-specific Service Information) and Refer to A/C SYSTEM, OPERATING AFTER CHARGING .