A/C Service Station, Connecting

WARNING: This page does not describe the selected car, but rather 17 other vehicles, including the 2009 Audi S4, 2009 Audi A4, 2008 Audi S4, 2008 Audi RS 4, and 2008 Audi A4. However, it is still accessible from the selected car via links, so may be relevant.

Vehicles with Connection on Low- and High-Pressure Side of Refrigerant Circuit

Switch off ignition.

Connect A/C service station to power supply.

Connect quick-release coupling adapter to charging hoses of A/C service station (handwheels not screwed in/hand shut-off valve not open).

Switch on A/C service station and evacuate charging hoses (only necessary if there is air in hoses).

Switch off A/C service station.

Unscrew caps from service connections (with valve).

Connect A/C service station via service connections with quick-release coupling adapters to vehicle refrigerant circuit.

Screw in handwheel of quick-release coupling adapters until valves are definitely open at refrigerant circuit connection (observe pressure gauge, do not strain valves).

Perform planned tests and measurements.

Vehicles with no Connection on Low-Pressure Side of Refrigerant Circuit

On the following vehicles, no service connection is provided for the A/C service station on the low-pressure side of the refrigerant circuit. Adapters are required for connecting the A/C service station to the refrigerant circuit of these vehicles.

Audi 80, Audi Cabrio, Audi Coupe

Audi A4 up to 07.96

Audi 100/ Audi A6 up to 03.97

Audi A8 up to 11.97

NOTE:

On vehicles with no or inaccessible connection at compressor, remove A/C Refrigerant Low Pressure Switch F73 (jumper contacts in connector for A/C Refrigerant Low Pressure Switch F73 ) and screw adapter to this connection → 87 - Air conditioning .

NOTE:

The tools listed below are commercially available or can be obtained from regional sales center/importer.
Should it be necessary to measure pressures at switch connections on high-pressure side, make use of adapter from adapter set for refrigerant circuit V.A.G /9 and proceed in the same manner.

Fig 1: Connecting With Air Conditioning Adapter Set V.A.G 1786

Courtesy of VOLKSWAGEN UNITED STATES, INC.

Connecting with Air Conditioning Adapter Set V.A.G 1786

A - Connection with valve (small valve insert) on low-pressure side of refrigerant circuit

B - Adapter with union nut V.A.G /1

C - Commercially available charging hose (short version with 5/8" thread on each end)

D - Adapter with service connection V.A.G /2 (for connection of quick-release coupling of A/C service station - E - )

NOTE:

Assemble adapter and charging hose as shown and connect first to connection with valve - A -.
Adapter with union nut V.A.G /1 is only to be used at connections with "small" valve insert (standard for connection with valve for A/C Refrigerant Low Pressure Switch F73 and also gradually introduced as of 10.94 at compressor).
Instead of adapter with union nut V.A.G /1 , use can also be made of adapter V.A.G /10 (remove valve from adapter V.A.G /10 or install valve opener in charging hose).

Connecting with Adapter VAG/10

Fig 2: Connecting With Air Conditioning Adapter Set VAG/10

Courtesy of VOLKSWAGEN UNITED STATES, INC.

Unscrew cap from connection with valve - A - (at compressor).

Attach O-ring - B - to connection (8.9 mm; 1.8 mm).

Screw adapter V.A.G /10 - C - to connection - B -.

Install valve opener - D - with appropriate seal in charging hose connection.

NOTE:

The type of valve opener - D - and seals required depends on the charging hose used (specific to manufacturer).
The quick-release coupling adapter is not required for connection on the low-pressure side of Audi vehicles.
Screw charging hose - E - (to A/C service station) to adapter V.A.G /10.

Fig 3: Identifying Charging Hoses Should Be Connected Together

Courtesy of VOLKSWAGEN UNITED STATES, INC.

NOTE:

To minimize the amount of air and moisture penetrating into the charging hoses and thus into the refrigerant circuit, the charging hoses should be connected together as illustrated.

A - Charging hose to A/C service station

B - Hand shut-off valve

C - Charging hose (short version) with valve opener for connection to adapter - D -

D - Adapter V.A.G /10

E - Charging hose (short version) with quick-release coupling adapter (for vehicles with quick-release coupling adapter on low-pressure side)

Perform planned tests and measurements.