A/C Service Station, Switching Off And Disconnecting From Refrigerant Circuit
-- End the specified procedures using the A/C Service Station.
-- Switch off the ignition.
-- Remove (seal) the hand wheels for both service couplings.
Danger of frostbite due to refrigerant coming out under pressure.
Frostbite on the skin and other parts of the body is possible.
- Wear safety gloves.
- Wear protective eyewear.
- 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 have elapsed since evacuating the refrigerant and the refrigerant circuit was not opened, evacuate the refrigerant again. Evaporation can cause pressure to develop in the refrigerant circuit.
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 removing the hand wheel for these service couplings, first the valve in the vehicle service connection is closed, and 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. 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. On this version, no refrigerant escapes when turning back the service coupling hand wheel; therefore, the refrigerant from the filling hoses must be extracted back in the A/C Service Station before disconnecting the service couplings. If a larger amount of refrigerant is recovered (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 (evacuate the refrigerant and replace the faulty valve).
Before extracting back the refrigerant from the filling hoses in the A/C Service Station, remove the hand wheels from both service couplings all the way.
There is a function in the A/C Service Station which will bring the service station into a specific operating condition when switching it off. Via this function the entire refrigerant is extracted back out of the filling hose in the A/C Service Station.
If when activating this function the hand wheel of both service coupling cannot be removed, refrigerant can be extracted from the vehicle refrigerant circuit.
-- Use the A/C Service Station to extract the refrigerant from both filling hoses according to the operating instructions. Refer to A/C Service Station Operating Instructions.
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 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, this indicates a malfunction in one of the valves in the service coupling.
Incorrectly evacuating the vehicle refrigerant circuit.
-- First remove (close) the hand wheels from the quick-release coupling adapter.
-- Then extract refrigerant from both filler hoses using the A/C service station.
-- Switch off the A/C Service Station (and if necessary disconnect from the power supply). Refer to A/C Service Station Owner's Manual.
-- Disconnect the quick-release couplings to the refrigerant circuit service connections.
-- Install the closure caps on the service connections (refer to the vehicle-specific refrigerant circuit). Refer to SYSTEM OVERVIEW - REFRIGERANT CIRCUIT, R1234YF .