Working With A/C Service Station
If it is suspected that chemicals were added to the refrigerant circuit to seal leaks, chemical substances to seal leaks in the refrigerant circuit (leak stop additive), do not connect the A/C service station and do not extract the refrigerant.
Chemicals that seal leaks in the coolant circuit form deposits that affect the function of the A/C system and lead to failure of the A/C system and the A/C service station.
More the customer aware that there are substances in their A/C system which are not approved by Volkswagen/Audi and for this reason this A/C system cannot be discharged and serviced.
The chemical materials (leak stop additive) for sealing leaks in the refrigerant circuit offered on the market are not approved by Volkswagen/Audi. There are no permanent -, validity or material compatibility tests. Therefore damage or malfunctions in the A/C system or the A/C service station cannot be excluded.
The stop leak additives offered on the open market have different physical and chemical properties, which can impair the function of the A/C system and the A/C service station and can even shut down the system completely. Volkswagen/Audi does not approve the use of chemicals to seal leaks in the refrigerant circuit (leak stop additives).
Chemical materials to seal leaks in the refrigerant circuit react with air or the moisture in the air and form deposits in the refrigerant circuit (and the A/C service station) that lead to malfunctions in the valves and other components that come into contact with such chemicals. These deposits cannot be removed completely from the components, even by flushing.
It is not possible to recognize chemical substances to seal leaks in the refrigerant circuit (leak stop additive) and the label that is supposed to come with them is usually not there. Therefore be careful when working with a vehicle if its service history is unknown.
Accessories offer containers used to separate out these chemicals (used to seal leaks in the refrigerant circuit). Since Volkswagen/Audi does not know composition and the physical and chemical properties of these materials, it is not possible to make a statement about their effectiveness and the deposition rate of these filters.
If the refrigerant circuit gets filed with a chemical material (stop leak additive) to seal any leaks (or if there is a suspicion of this) and if it then necessary to perform a repair to the refrigerant circuit, then it is necessary to inform the customer of the following:
- It is not possible to evacuate the refrigerant from the A/C system due to the stop leak additive that has been added to the system because it will damage the A/C service station. When extracting the refrigerant it can be filled as contaminated refrigerant as described in recycling bottles. Refer to CONTAMINATED REFRIGERANT, FILLING IN RECYCLING CONTAINER FOR ANALYSIS, PROCESSING, OR DISPOSAL . If it is not possible an outside company for example must evacuate the contaminated refrigerant with a suitable device and extract it from the refrigerant circuit after completing the preparation (or the disposal) (for example, a local waste management company that specializes in disposing of refrigerant).
- It will be necessary to replace any refrigerant circuit components that have come in contact with the stop leak additive in order to repair the A/C system properly. Certain refrigerant circuit components may already be damaged by the stop leak additive (for example, the A/C Compressor Regulator Valve -N280-) or will get damaged if they are used over again and will fail after a short amount of time. In addition to this, if there is any sediment from the stop leak additive still in the circuit, it could come loose at a later point and cause the A/C system to fail again (currently it is not possible to clean these components with any workshop tools).
- Contaminated refrigerant can make the entire filling of the A/C service station unusable.
- Before extracting with a suitable tester check the composition of the refrigerant in the refrigerant circuit. Refer to REFRIGERANT GAS ANALYSIS, PERFORMING .
- Extract contaminated refrigerant in a recycling bottle and return it to the gas supplier to be analyzed, processed or disposed of. Refer to RETURN OF CONTAMINATED REFRIGERANT R1234YF FOR ANALYSIS, PREPARATION OR DISPOSAL .
Damaged refrigerant can change the A/C system function and/or damage the refrigerant circuit components.
Mixing different refrigerant (for example refrigerant R1234yf with a certain percentage of refrigerant R134a) my not be filled in a vehicle which was type-tested with refrigerant R1234yf.
Important Information when Working with A/C Service Station
Pay attention to the following to start the A/C service station (currently available A/C service station. Refer to Special Tools and Equipment Information.)
- The filters and dryers installed must be replaced, at the latest, when the service life specified in the relevant operating instructions has been reached.
- If an A/C service station is also used for cleaning (flushing) the refrigerant circuit, dryer and filter must be replaced in shorter intervals. Refer to REFRIGERANT CIRCUIT, FLUSHING WITH COMPRESSED AIR OR NITROGEN .
- In the reservoir exclusive use is to be made of refrigerant oils which have been approved for the vehicle-specific refrigerant circuit (if necessary, fill refrigerant oil directly into refrigerant circuit). Refer to Parts Information.
- Depending on the version of the A/C service station and the procedures to be performed a specific minimum amount of refrigerant, refrigerant oil and UV-leak detection are in the corresponding reservoir of the A/C service station. Refer to the A/C service station Owner's Manual.
Extracted refrigerant is not to be reused if there is any doubt about the composition of the refrigerant extracted, even after cleaning in the A/C service station. Refer to REFRIGERANT GAS ANALYSIS, PERFORMING .
- If the wrong refrigerant is accidentally filled in the A/C service station it must be discharged. The system must be cleaned and the filter and dryer as well at the filled refrigerant oil is to be replaced. Refer to REFRIGERANT CIRCUIT, DISCHARGING and A/C SERVICE STATION ON REFRIGERANT CIRCUIT, CONNECTING .
- For example, within Germany, contaminated refrigerant can be returned to the supplier in recycling containers for analysis, recycling or for environmentally safe disposal. Other or additional regulations may apply in other countries. Refer to RETURN OF CONTAMINATED REFRIGERANT R1234YF FOR ANALYSIS, PREPARATION OR DISPOSAL .