A/C Service Station, Switching Off And Disconnecting From Refrigerant Circuit
- Pay attention to the information on switching off and disconnecting the A/C Service Station from the refrigerant circuit. Refer to the A/C Service Station Operating Instructions.
-- End the specified procedures using the A/C Service Station.
-- Deactivate drive ready mode and switch off all electrical equipment.
-- Wait until the pressures on the low- and high-pressure side have equalized.
Risk of frostbite, asphyxiation and poisoning due to refrigerant coming out under pressure.
In addition to frostbite on the skin and other parts of the body, refrigerant fumes can cause problems ranging from a dry cough and nausea to asphyxiation and poisoning.
- Wear safety gloves.
- Wear protective eyewear.
- Never breathe in refrigerant fumes.
- If refrigerant leaks out of the refrigerant line for longer than 1 second when loosening the service coupling hand wheel, screw in the hand wheel and replace the faulty valve.
- Extract refrigerant and open the refrigerant circuit immediately.
- If more than 10 minutes elapse after extracting the refrigerant and the refrigerant circuit was not opened, extract the refrigerant again. Evaporation can cause pressure to develop in the refrigerant circuit.
-- Unscrew (seal) the hand wheels for both service couplings.
Different Service Coupling Versions
- When unscrewing the hand wheel for one service coupling version, the space between the valve in the refrigerant circuit service connection and the valve in the service coupling is vented outward. When unscrewing the hand wheel for these service couplings, first the valve in the vehicle service connection is closed, and then the valve in the service coupling to the A/C Service Station filler hose is closed. Any pressure still in the space between both valves is then discharged via another valve (approximately 2 cm3 of refrigerant) when continuing to unscrew. If one of these two valves (the valve on the vehicle service connection or the valve in the filler hose service coupling) do not close correctly, all of the refrigerant can flow out of the vehicle refrigerant circuit or the filler hose.
- When unscrewing the hand wheel on the other service coupling version, the space between the valve in the refrigerant circuit service connection and the valve in the service coupling is not vented outward. This service coupling version generally cannot be uncoupled as long as there is pressure in the area between the valve in the service connection and the service coupling (it is mechanically locked). On this version a valve is present, which on a connected service coupling is open, so that a pressure equalization between the area in the valve in the refrigerant circuit service connection and the filler hose connected on the service connection is possible. For this version, no refrigerant flows out when turning back the service coupling hand wheel; therefore, the refrigerant must be discharged here from the filling hoses via the A/C Service Station before decoupling the service couplings. If a larger amount of refrigerant is discharged (more than approximately 50 g (1.8 oz)) here, for example after a pressure test or charging the refrigerant circuit, this indicates that there may be a valve leaking in one of the refrigerant circuit service connections and refrigerant is leaking out of the vehicle refrigerant circuit (discharge the refrigerant and replace the faulty valve).
-- Before venting the refrigerant from the filling hoses to the A/C Service Station, unscrew the hand wheels on both service couplings until they stop.
-- Use the A/C Service Station to discharge the refrigerant from both filling hoses according to the operating instructions. Refer to A/C Service Station Operating Instructions.
- If when activating this function the hand wheel of both service coupling cannot be removed, refrigerant can be extracted from the vehicle refrigerant circuit.
- If on an A/C Service Station with a service coupling, by which the pressure is not removed outward, this procedure takes longer than two minutes or a large quantity or refrigerant is extracted, this indicates a malfunction in one of the valves in the service connection.
- If this procedure lasts longer than approximately two minutes on an A/C Service Station with a service coupling that releases pressure outward, then this indicates incorrect handling (the hand wheels were not completely unscrewed) or a malfunction at one of the valves in a service coupling.
-- Switch off the A/C Service Station (and disconnect it from the power supply if necessary). Refer to the A/C Service Station Owner's Manual.
-- Disconnect the quick-release couplings to the refrigerant circuit service connections.
-- Install the caps on the service connections (refer to the vehicle-specific refrigerant circuit). Refer to Refrigerant Circuit (vehicle-specific Service Information).