Volkswagen Golf Service & Repair Manual: Principle circuit diagrams for various purging circuits

Volkswagen Golf Service & Repair Manual / Air conditioning system with refrigerant R134a / Clearing refrigerant circuit of contaminants / Purging (cleaning) refrigerant circuit with refrigerant R134a / Principle circuit diagrams for various purging circuits

Note

The arrows in the following illustrations show the direction of flow of the refrigerant during purging. The refrigerant flows against the direction of flow during normal conditioning of the air, which is why the high-pressure system of the air conditioner service station is connected to the low-pressure connection of the refrigerant circuit to the air conditioner compressor.

These principle circuit diagrams show a refrigerant circuit with restrictor and reservoir and a refrigerant circuit with expansion valve, receiver and a second evaporator (extra equipment on certain vehicles).

Depending on the design of the air conditioner service station, non-return valves may be installed between the refrigerant circuit and the air conditioner service station. This ensures the correct direction of flow of refrigerant during purging.

Refrigerant circuit with restrictor and reservoir

Note

On vehicles with restrictor and reservoir, the restrictor and the reservoir are removed. The refrigerant pipes of the restrictor are assembled again. The refrigerant pipes to the removed reservoir are joined together with two adapters and the charging hose -VAS 6338/31- (from adapter case VW/Audi passenger vehicle set -VAS 6338/1-.

Principle circuit diagrams for various purging circuits

1 -	Air conditioner service station

With electronics and a purging programme e.g. air conditioner service station -VAS 6380- with purging device or air conditioner service station with purging device -VAS 6337-.

If an air conditioner service station without purging programme is used, the sequence has to be carried out manually (evacuate, purge 3 times with at least 4 kg of refrigerant each time and extract refrigerant again, evacuate).

2 -	Refrigerant hose of air conditioner service station

From high pressure side of air conditioner service station (normally coloured red) to connection for low pressure side of air conditioner compressor on refrigerant circuit (larger diameter)

3 -	Adapter to connection for low-pressure side on refrigerant circuit

Different versions depending on vehicle → Chapter.

From adapter case VW/Audi passenger vehicle set -VAS 6338/1-.

4 -	Connection for low-pressure side on refrigerant circuit

Different versions depending on vehicle → Chapter.

On refrigerant line from air conditioner compressor to reservoir

5 -	Connection to reservoir

Different versions depending on vehicle → Chapter.

On refrigerant line from air conditioner compressor to reservoir

6 -	Adapter to bridge removed reservoir

Different versions depending on vehicle → Chapter.

From adapter case VW/Audi passenger vehicle set -VAS 6338/1-.

7 -	Charging hose for refrigerant → Chapter

For example charging hose -VAS 6338/31- (from adapter case VW/Audi passenger vehicle set -VAS 6338/1-).

8 -	Adapter to bridge removed reservoir

Different versions depending on vehicle → Chapter.

From adapter case VW/Audi passenger vehicle set -VAS 6338/1-.

9 -	Connection to reservoir

Different versions depending on vehicle → Chapter.

10 -	Evaporator

11 -	Location of restrictor

The restrictor is removed.

Removing restrictor → Heating, air conditioning.

12 -	Threaded connection in refrigerant line

After removing the restrictor, screw back together again → Heating, air conditioning.

13 -

Condenser

14 -	Connection for high-pressure side on refrigerant circuit

Different versions depending on vehicle → Chapter.

15 -	Adapter to connection for high-pressure side on refrigerant circuit

Different versions depending on vehicle → Chapter.

From adapter case VW/Audi passenger vehicle set -VAS 6338/1-.

16 -	Charging hose of flushing device for refrigerant circuits

From connection to high-pressure side of air conditioner compressor on refrigerant circuit (smaller diameter) to inlet of purging device for refrigerant circuits -VAS 6336/1- or purging device for refrigerant circuits -VAS 6337/1-.

17 -	Purging device for refrigerant circuits

Different versions and different design e.g. purging device for refrigerant circuits -VAS 6336/1- or purging device for refrigerant circuits -VAS 6337/1-.

With filter, sight glass, safety valve, heating, refrigerant tank, etc. (depending on version).

Depending on the design of the air conditioner service station and the purging device for refrigerant circuits, there may be a non-return valve installed at the outlet of the purging device for refrigerant circuits (to assure the correct direction of refrigerant flow during purging).

18 -	Refrigerant hose of air conditioner service station

From the low-pressure side of the air conditioner service station (normally coloured blue) to the outlet of the purging device for refrigerant circuits

Refrigerant circuit with expansion valve, receiver and second evaporator

Note

This principle circuit diagram shows a refrigerant circuit with expansion valve, receiver and a second evaporator (extra equipment on certain vehicles).

On vehicles with expansion valve and receiver, the expansion valve is removed and an adapter installed in its place. The receiver must be purged, depending on the vehicle or the dryer cartridge removed. Depending on the type of receiver, this should be removed and the line connections to the receiver joined together using two adapters and a charging hose.

On vehicles with just one evaporator, the components from position “16” are not installed or not required.

Principle circuit diagrams for various purging circuits

1 -	Air conditioner service station

With electronics and a purging programme e.g. air conditioner service station -VAS 6380- with purging device or air conditioner service station with purging device -VAS 6337-.

–

If an air conditioner service station is used which does not have a purging programme, then the sequence must be performed manually.

–	Extract refrigerant, if there is any in the system.

–	Connect purging device for refrigerant circuits -VAS 6336/1- or purging device for refrigerant circuits -VAS 6337/1- between air conditioner service station and return line for refrigerant circuit.

–	Evacuate refrigerant circuit for 20 minutes, then fill system with 4 kg of refrigerant R134a. Then extract again and repeat process two further times. If after the 3rd purging process the refrigerant in the sight glass/glasses is not clear, repeat process again.

2 -	Refrigerant hose of air conditioner service station

From high pressure side of air conditioner service station (normally coloured red) to connection for low pressure side of air conditioner compressor on refrigerant circuit (larger diameter)

3 -	Adapter to connection for low-pressure side on refrigerant circuit

Different versions depending on vehicle → Chapter.

From adapter case VW/Audi passenger vehicle set -VAS 6338/1-.

4 -	Connection for low-pressure side on refrigerant circuit

Different versions depending on vehicle → Chapter.

5 -	Adapter for removed expansion valve

Different versions depending on vehicle → Chapter.

From adapter case VW/Audi passenger vehicle set -VAS 6338/1-.

6 -	Evaporator

7 -	Connection to receiver

Different versions depending on vehicle → Chapter.

Not included on vehicles with a dryer cartridge in the receiver on the condenser or one in the receiver integrated within the condenser → Heating, air conditioning.

8 -	Adapter to bridge removed receiver

Not required on all vehicles.

Different versions depending on vehicle → Chapter.

From adapter case VW/Audi passenger vehicle set -VAS 6338/1-.

9 -	Charging hose for refrigerant → Chapter

For example charging hose -VAS 6338/31- (from adapter case VW/Audi passenger vehicle set -VAS 6338/1-).

10 -

Condenser

If there is a receiver with dryer cartridge installed on the condenser, the dryer cartridge must be removed (seal receiver again on or in condenser following removal) → Heating, air conditioning.

If the receiver is attached directly to the condenser, remove the receiver after purging and renew → Heating, air conditioning.

11 -	Connection for high-pressure side on refrigerant circuit

Different versions depending on vehicle → Chapter.

12 -	Adapter to connection for high-pressure side on refrigerant circuit

Different versions depending on vehicle → Chapter.

From adapter case VW/Audi passenger vehicle set -VAS 6338/1-.

13 -	Charging hose of flushing device for refrigerant circuits

From connection to high pressure side of air conditioner compressor on refrigerant circuit (smaller diameter) to inlet of purging device for refrigerant circuits.

14 -	Purging device for refrigerant circuits

Different versions and different design e.g. purging device for refrigerant circuits -VAS 6336/1- or purging device for refrigerant circuits -VAS 6337/1-.

With filter, sight glass, safety valve, heating, refrigerant tank, etc. (depending on version).

15 -	Refrigerant hose of air conditioner service station

From the low-pressure side of the air conditioner service station (normally coloured blue) to the outlet of the purging device for refrigerant circuits

16 -	Adapter to seal outlet to second evaporator

Only required on certain vehicles with “second evaporator” (optional equipment).

From adapter case commercial vehicle set -VAS 6338/50-.

17 -	Adapter to seal outlet to second evaporator

Only required on certain vehicles with “second evaporator” (optional equipment).

From adapter case commercial vehicle set -VAS 6338/50-.

18 -	Connection of low-pressure side on refrigerant circuit to second evaporator

Different versions depending on vehicle → Chapter.

Only fitted on certain vehicles with “second evaporator” (optional equipment).

19 -	Connection of high-pressure side on refrigerant circuit to second evaporator

Different versions depending on vehicle → Chapter.

Only fitted on certain vehicles with “second evaporator” (optional equipment).

20 -	Adapter for removed expansion valve on second evaporator

Different versions depending on vehicle → Chapter.

Only required on certain vehicles with “second evaporator” (optional equipment).

From adapter case commercial vehicle set -VAS 6338/50-.

21 -	Second evaporator

Only fitted on certain vehicles with “second evaporator” (optional equipment).

Purging (cleaning) refrigerant circuit with refrigerant R134a

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