Expansion Valve and Receiver (With Internally Regulated Compressor), Checking

Expansion Valve And Receiver (With Internally Regulated Compressor), Checking

NOTE:
- Connect service station. Working With Service Station
- Observe test conditions. Pressures In Refrigerant Circuit, Checking (Using Service Station)

- Set engine speed to 2000 RPM.
- Observe pressure gauge set.

NOTE: Switching pressures and arrangement of refrigerant circuit switches are vehicle-specific.

Pressures must be measured at service connections; component locations of these connections are vehicle-specific

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 in bar
B. Low pressure in bar
C. Permissible tolerance range.







NOTE: If no malfunction can be found and air conditioner operation is not OK when test is repeated, flush refrigerant circuit with compressed air and nitrogen.







NOTE: If operation is not OK after refrigerant circuit has been flushed, expansion valve must be replaced.







NOTE: Always replace receiver for this malfunction.







NOTE: If the function of the air conditioning system is not OK when the test is repeated, reinstall old expansion valve and flush refrigerant circuit with compressed air and nitrogen. Then replace A/C compressor and receiver.







NOTE:
- If the function of the air conditioning system is not OK when the test is repeated, reinstall old expansion valve and flush refrigerant circuit with compressed air and nitrogen. Then replace A/C compressor and receiver.
- With this malfunction, evaporator may ice up although quantity of refrigerant in circuit is OK.







NOTE: Overfilling with refrigerant oil can occur if, for example, the compressor has been replaced without adjusting the quantity of refrigerant oil.