Restrictor and Reservoir With Internally Regulated A/C Compressor, Checking

Restrictor and Reservoir with Internally Regulated 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.