Refrigerant Circuit With A/C Service Station, Draining
- If it is suspected that chemicals were added to the refrigerant circuit to seal leaks, 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.
- Inform that customer that there are substances in the A/C system that are no approved by Volkswagen. This A/C system cannot be drained or serviced in the workshop.
The chemical materials (stop leak additive) for sealing leaks in the refrigerant circuit offered on the market are not approved by VW Audi AG. 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.
VW does not approve the use of chemicals to seal leaks in the refrigerant circuit.
Chemicals used to seal leaks in the refrigerant circuit often react with air and the moisture in it. They cause deposits in the refrigerant circuit and the A/C service station and malfunctions in valves and other components that they come in contact with. These deposits cannot be removed completely from the components.
Chemicals used to seal leaks in the refrigerant circuit usually cannot be detected from outside. The label that should be applied to identify it is often missing. Therefore be careful when working with if you do not know its service history.
Accessories offer containers used to separate out these chemicals (used to seal leaks in the refrigerant circuit). Because VW does not approve the use of these chemicals, there is no evidence of the effectiveness of these filters.
- The work procedure is always to be performed as described in the operating instructions for the A/C service station.
- The procedure described here is for the A/C Service Station VAS 6007A.
Before filling the refrigerant circuit with refrigerant, it should be evacuated (vacuum) for 45 minutes on systems with 1 evaporator and 60 minutes on systems with 2 evaporators. Moisture is also extracted from the circuit.
Leaks may be found when evacuating the refrigerant circuit.
Evacuating:
- Do not start the engine during the evacuation process or when there is a vacuum in the refrigerant circuit.
- The A/C compressor could be damaged if the engine is started when there is a vacuum in the refrigerant circuit.
- Only start the engine when the refrigerant circuit is filled.
-- Turn off the ignition.
-- Check refrigerant oil quantity in refrigerant circuit if necessary, see vehicle-specific Repair Information, refer to DESCRIPTION AND OPERATION .
-- Connect the A/C service station to the power supply.
-- Check the amount of refrigerant in the A/C service station.
-- Connect charging hose of A/C service station to vehicle refrigerant circuit with quick-release coupling adapter (refer to vehicle-specific refrigerant circuit).
Refer to REFRIGERANT CIRCUIT .
-- Only tighten the handwheel on the quick-release coupling adapter just enough so the valves in the service connections are securely open. Do not put too much pressure on the valve.
If pressure is to be measured after charging system on vehicles with a service connection on one side of the refrigerant circuit only, use valve adapter and charging hose with valve opener.
-- Initiate the vacuum phase on the A/C service station. The refrigerant circuit is automatically evacuated. Check the preset evacuating time if necessary.
When the vacuum phase ends, the refrigerant circuit leak test begins. Pressure in bar and seconds are displayed.
Proceed as follows if the vacuum is not maintained:
-- Initiate the vacuum phase on the A/C service station again. The refrigerant circuit is automatically evacuated. Check the preset evacuating time if necessary. Watch the vacuum indicator for an extended period of time. Only when the vacuum is maintained can the refrigerant circuit be charged.
- If there is a leak that allowed enough air to enter during evacuation that the A/C service station cannot generate a sufficient vacuum or that the vacuum is lost immediately after switching the A/C service station off:
-- Determine the location of the leak in the refrigerant circuit, refer to REFRIGERANT CIRCUIT, DETECTING LEAKS .