Main Wiring Diagram For Cleaning (Flushing), Refrigerant Circuit With Expansion Valve And Receiver/Dryer

WARNING: This page is about a different car, the 2023 Volkswagen Atlas. However, it is still accessible from the selected car via links, so may be relevant.

With 1 or 2 evaporators
Without or with high-voltage system

During flushing, the refrigerant flows in the opposite direction than during A/C system operation, therefore the high pressure side of the A/C Service Station is connected to the low pressure connection of the refrigerant circuit leading to the A/C compressor.
For vehicles with two evaporators, the refrigerant circuit to the second evaporator must be disconnected from the refrigerant circuit of the first evaporator and must be flushed via a separate work procedure. Refer to ADAPTER FOR ASSEMBLING FLUSHING CIRCUIT .
For vehicles with an evaporator and a heat exchanger, disconnect the circuit to the heat exchanger via the manual shut-off valves from the circuit of the first evaporator and to be flushed in a separate work process. Refer to ADAPTER FOR ASSEMBLING FLUSHING CIRCUIT .

The arrows indicate the refrigerant flow direction during cleaning.
This main wiring diagram shows a refrigerant circuit with expansion valve, receiver/dryer and second evaporator (optional equipment on certain vehicles).

Fig 1: Block Diagram For Flushing Circuits (Type 1)

Courtesy of AUDI OF AMERICA, LLC

A/C Service Station
Refrigerant Hose for A/C Service Station
- From the high pressure side of the A/C Service Station (mostly red colored) to the low pressure side connection of the A/C compressor on refrigerant circuit (larger diameter).
Adapter to Connection for Low Pressure Side on Refrigerant Circuit
- ADAPTER FOR ASSEMBLING FLUSHING CIRCUIT
- use the Refrigerant Circuits Adapter Set - Adapter 48:VAS 6338/48 between the refrigerant hose -2- and the adapter -3-.
- depending on the version of the adapter an additional adapter is necessary to connect the A/C Service Station filling hose.
Low Pressure Side Connection on Refrigerant Circuit
- Connect to MAIN WIRING DIAGRAM FOR CLEANING (FLUSHING), REFRIGERANT CIRCUIT WITH EXPANSION VALVE AND RECEIVER/DRYER List Item:Adapter to Connection for Low Pressure Side on Refrigerant Circuit
Adapter for Removed Expansion Valve
- ADAPTER FOR ASSEMBLING FLUSHING CIRCUIT
Evaporator
Connection to Receiver/Dryer
- installed depending on the vehicle
- Not present on vehicles with a dryer cartridge in the receiver/dryer on the condenser or with a receiver/dryer installed in the condenser. Refer to Refrigerant Circuit .
- ADAPTER FOR ASSEMBLING FLUSHING CIRCUIT
Adapter for Bridging Removed Receiver/Dryer
- Necessary depending on the vehicle
- ADAPTER FOR ASSEMBLING FLUSHING CIRCUIT
Filler Hose
- For example Filler Hose from Refrigerant Circuits Adapter Set 1: VAS 6338/1 . Refer to ADAPTER FOR ASSEMBLING FLUSHING CIRCUIT .
Condenser
- If the receiver/dryer is attached directly to the condenser, the receiver/dryer must be removed and replaced only after flushing. Refer to Refrigerant Circuit (vehicle-specific service information).
- If a receiver/dryer with dryer cartridge is installed on the condenser, the dryer cartridge must be removed (reseal the receiver/dryer at or in the condenser after removing). Refer to Refrigerant Circuit (vehicle-specific service information).
- On certain vehicles the receiver/dryer is integrated inside the condenser and the dryer cartridge cannot be replaced separately and is not available as a single part. In this case, the condenser with receiver/dryer/dryer cartridge must be replaced after flushing. Refer to Refrigerant Circuit .
High Pressure Side Connection on Refrigerant Circuit
- Connect to MAIN WIRING DIAGRAM FOR CLEANING (FLUSHING), REFRIGERANT CIRCUIT WITH EXPANSION VALVE AND RECEIVER/DRYER List Item:Adapter to Connection for High-Pressure Side on Refrigerant Circuit
Adapter to Connection for High-Pressure Side on Refrigerant Circuit
- ADAPTER FOR ASSEMBLING FLUSHING CIRCUIT
Charging Hose for Refrigerant Circuit Flushing Device
- from the connection to the high pressure side of the A/C compressor on the refrigerant circuit (smaller diameter) to the input of the flushing device.
Flushing Device
- different versions and design
- with filter, viewing glass, safety valve, heater, refrigerant reservoir, etc. (depending on version).
- Depending on the construction of the A/C Service Station and of refrigerant circuit flushing device, a check valve may be installed at the output of the refrigerant circuit flushing device (to guarantee correct direction of refrigerant flow during flushing).
- depending on the flushing device a 5/8 -18 UNF external thread a connection for a R134a or a R1234yf high pressure service coupling can be present on the output for the A/C Service Station.
- on flushing devices with a 5/8 -18 UNF external thread or a connection for a R134a low pressure side service connection an additional adapter is necessary to connect the R1234yf low pressure side service connection or a filler hose to the A/C Service Station (with a M12 x 1.5-6G external thread according to SAE J639) to the output of the flushing device.
- The filler hose from the A/C Service Station has a M12 x 1.5-6G external thread according to SAE J639. On the flushing device for the refrigerant circuit there can be a service connection for a low pressure side service connection according to SAE J639 for the refrigerant R1234yf, a M12 x 1.5-6G inner thread according to SAE J639, a service connection for a R134a low pressure side service connection or a 5/8 -18 UNF external thread depending on the version. So that both components can be connected an additional adapter may be necessary.
Refrigerant Hose for A/C Service Station
- from the low pressure side of the A/C Service Station (mostly blue colored) to the output of the flushing device.
Adapter for Sealing Outlet to Second Evaporator
- Necessary depending on vehicle equipment. Refer to ADAPTER FOR ASSEMBLING FLUSHING CIRCUIT .
Adapter for Sealing Outlet to Second Evaporator
- Necessary depending on vehicle equipment. Refer to ADAPTER FOR ASSEMBLING FLUSHING CIRCUIT .
Low Pressure Side Connection on Refrigerant Circuit to Second Evaporator
- Necessary depending on vehicle equipment. Refer to ADAPTER FOR ASSEMBLING FLUSHING CIRCUIT .
High Pressure Side Connection on Refrigerant Circuit to Second Evaporator
- Necessary depending on vehicle equipment. Refer to ADAPTER FOR ASSEMBLING FLUSHING CIRCUIT .
Adapter for Removed Expansion Valve on Second Evaporator
- Necessary depending on vehicle equipment. Refer to ADAPTER FOR ASSEMBLING FLUSHING CIRCUIT .
Second Evaporator
- Installed depending on vehicle equipment