Add Refrigerant R1234Yf

Information 

Only use recommended air conditioning servicing equipment for R1234yf (see Workshop Equipment and Special Tools Information) 

Information 

The desiccator must be replaced in the following situations: 

• Refrigerant circuit is open for > 20 minutes.
• Amount of refrigerant extracted is < 30% of the required quantity.
• Refrigerant circuit has been open for an indefinite period of time (gradual leak, stone damage to condenser).
• Air-conditioning compressor has become blocked.
• Dryer cartridge is damaged.
• After opening the packaging and line connections (on a new desiccator), the desiccator must be installed within 20 minutes at the latest and the refrigerant circuit must be closed, evacuated and filled.

The desiccator must not be replaced in the following situations: 

• If the components are closed off using stoppers immediately after opening the refrigerant circuit or if the refrigerant circuit is closed and evacuated within 20 minutes at the latest.

1. Check whether the desiccator needs to be replaced.
2. Evacuate the system and check for leaks.
   1. 2.1 If the air-conditioning system was opened, evacuation must last at least 20 minutes, so that the moisture can evaporate and be extracted.
   2. 2.2 If the air-conditioning system has been open for a long time, evacuation can be carried out for up to 120 minutes.
   3. 2.3 Check the pressure gauge for approx. 2 minutes. If the pressure rises, air is entering the vehicle's air-conditioning system. The leak must be found and repaired. If the pressure remains constant: Add refrigerant oil.
   4. 2.4 For air conditioning service equipment with an integrated oil filling system: 

      Add the measured quantity of refrigerant oil and wait for it to be taken in.

3. Add refrigerant oil.
   1. 3.1 For air conditioning service equipment without an integrated oil filling system: 

      Start the vacuum pump. At the start of this vacuum phase, add the measured quantity of refrigerant oil using an oil injector or a hose disconnected from the air conditioning service equipment. Re-connect the hose to the air conditioning service equipment immediately after adding the oil.

   2. 3.2 Do not allow any air to be taken in.
4. Fill the air-conditioning system.
   1. 4.1 Add the specified amount of refrigerant using the air conditioning service equipment for R1234yf.

      > 8X00IN - TECHNICAL DATA FOR AIR-CONDITIONING SYSTEM WITH REFRIGERANT R134A AND R1234YF

      Information 

      The refrigerant in the high-pressure and low-pressure lines is part of the filling capacity of the refrigerant in the air-conditioning system in the vehicle.

5. Add refrigerant from both connection hoses to the air-conditioning system in the vehicle.
   1. 5.1 Close the valve on the high-pressure line and disconnect it from the vehicle.
   2. 5.2 Start the engine and air-conditioning system. When the pressure on both pressure gauges drops below 2 bar, close the valve on the low-pressure line and disconnect it from the vehicle.
   3. 5.3 Check the valves on the high-pressure and low-pressure filling connections using a leak detector.

      If there are no leaks at the valves:  Fit caps.

      If valves are leaking:  Repair the valves.