With Restrictor and Reservoir (With Internally Regulator A/C Compressor), Checking

With Restrictor And Reservoir (With Internally Regulator A/C Compressor), Checking

NOTE:
- Connecting service station.
- Observe test requirements.

- Bring engine speed up to 2000 RPM.
- Observe pressure gauge of A/C service station.

NOTE:
- Switching pressures for refrigerant circuit switches are vehicle-specific.
- Connection with valve for low-pressure switch or at evaporator is only to be used for vehicles with no service connection on low-pressure side and inaccessible connection at compressor or accumulator (measurement accuracy). Only applies to certain vehicles.

Specified values:

High-pressure side:
Increasing from initial pressure (on connecting pressure gauges) to max. 20 bar

Low-pressure side:







Decreasing from initial pressure (on connecting pressure gauges) to value in graph.
A - High pressure (measured at service connection) in bar
B - Low pressure (measured at connection with valve at compressor or accumulator) in bar
C - Permissible tolerance range
D - Low pressure (measured at connection with valve for low-pressure switch or at service connection) in bar
E - Permissible tolerance range







NOTE: If no malfunction is found with this complaint, flush (clean) refrigerant circuit with refrigerant R134a. If that is not possible in this workshop, flush refrigerant circuit with compressed air and remove moisture with nitrogen.










NOTE:
- For the malfunction "high pressure normal, low pressure too low", note the following:
- This fault may cause the evaporator to ice up or the A/C Refrigerant Low Pressure Switch F73 to shut off the compressor although the amount of refrigerant in the circuit is OK.







NOTE:
- Overfilling with refrigerant oil can occur in the event, for example, the compressor has been replaced without adjusting the quantity of refrigerant oil.
- If the A/C compressor is not replaced, the refrigerant oil should be drained from the A/C compressor via the drain plug (replace O-ring). Out of the entire quantity of refrigerant oil, 50 grams should be put in the A/C compressor and the rest in the refrigerant circuit.