| General Procedures Refrigerant centre Refrigerant analyzer | | -
CAUTION:The refrigerant analyzer must be used before recovery, otherwise the refrigerant centre may become contaminated. Contaminated refrigerant must be disposed of as hazardous waste. Always follow the manufacturer's instructions when using the refrigerant centre and the refrigerant analyzer. Unscrew and remove the protective caps from the A/C charging connections. | | | -
Pull back the catches of the quick-fit unions on the refrigerant centre lines. | | | -
NOTE:Larger inner diameter for high-pressure side. Smaller inner diameter for low-pressure side. Connect the refrigerant centre lines to the A/C charging connections. | | | -
WARNING:When recovering the refrigerant do not allow it to enter the atmosphere under any circumstances. NOTE:When removing components of the air conditioning system, calculate the residual quantity of refrigerant oil. For additional information, refer to Refilling refrigerant oil in this section. Recover the refrigerant from the A/C system via the low-pressure connection in accordance with the refrigerant centre manufacturer's instructions. | | | -
CAUTION:The A/C system must be evacuated for about 30 minutes before recharging, to ensure that it operates correctly. CAUTION:If moisture was able to enter an open system over an extended period (several hours), install a new accumulator/dehydrator and increase the evacuation time to 2-3 hours. Evacuate the A/C system according to the refrigerant centre manufacturer's instructions. | | | -
NOTE:If an air conditioning system that was filled with refrigerant is being evacuated, some refrigerant will still be in the refrigerant oil in the compressor. This remaining refrigerant may evaporate, causing a slight increase in pressure during the leak test. The system is leak-free provided, that this pressure increase does not exceed 20 mbar (2 kPa, 0.29 psi). Perform the leak test. - For the leak test, close the hand valves on the pressure gauge set, switch off the refrigerant centre vacuum pump and observe the low pressure gauge.
- Locate any leaks in the A/C refrigerant circuit using a leak tester.
For additional information, refer to Leak detection with electronic leak tester /
Leak detection with fluorescent tracer dye in this section.
| CAUTION:The air conditioning system must always be evacuated before charging. | | -
NOTE:Depending on the type of refrigerant centre and the equipment (with or without heated filling cylinder), the air conditioning system is either charged with liquid via the high-pressure connection or with gas through the low-pressure connection. NOTE:Charge quantity on sticker in engine compartment. Charging the A/C system (with liquid) via the high-pressure connection. - Open the shut-off valve on the high-pressure side.
- Switch the refrigerant centre to "Fill" mode and fill with the prescribed quantity of liquid refrigerant (R134a).
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CAUTION:Only gaseous charging of the air conditioning system is performed via the low-pressure connection. Charging the A/C system via the low-pressure connection. - Open the shut-off valve on the low-pressure side.
- Switch the refrigerant centre to "Fill" mode and charge with gaseous refrigerant.
- Top up with the remaining amount of refrigerant whilst the air conditioning is switched on. For this purpose, run the engine at approx. 1200-1500 rpm. Switch the air conditioning to maximum cooling power and fresh air mode. Set the blower to maximum speed. Fill with the remainder of the prescribed fill capacity.
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WARNING:Do not detach the high-pressure hose when the air conditioning is switched on. Disconnecting the refrigerant centre. - Close the shut-off valves.
- Switch off the refrigerant centre.
- Disconnect the refrigerant centre lines from the A/C system charging connections.
- Attach the protective caps to the filling valves.
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