Expansion Block/Orifice Tube: Service and Repair

Receiver or Reservoir and Restrictor, Replacing

Replacing after flushing refrigerant circuit, e.g. on account of ingress of moisture (refrigerant circuit open for lengthy period) or contamination
- Discharge refrigerant circuit.
- Remove A/C compressor.
- Rectify cause of trouble.
- Clean (flush) refrigerant circuit with compressed air and nitrogen.
- Examine expansion valve for dirt or corrosion; replace if necessary.
- Remove oil drain plug from compressor.

NOTE: The oil drain plug of "Denso/Nippondenso" compressors is installed with an oil seal instead of an O-ring and this is always to be replaced


- To accelerate drainage of refrigerant oil, rotate compressor e.g. by way of clutch plate of A/C clutch for example.
- Pour old refrigerant oil out of compressor, see HSO Environment Vol. 2-2. 43. 1.
- Then fill compressor with quantity of fresh refrigerant oil corresponding to quantity of refrigerant oil in replacement compressor.

NOTE:
- Use different refrigerant oils and quantities for the various compressors.
- To ensure compressor lubrication on start-up, at least 80 cu.cm of refrigerant oil must be poured into the compressor, the remainder can be added for example to the new reservoir or receiver.
- If dirt has penetrated into the compressor with the refrigerant circuit open (e.g. after an accident), compressor is to be replaced.

- Replace receiver or reservoir and restrictor.
- Assemble, evacuate and charge refrigerant circuit.

Replacing without the need for flushing refrigerant circuit with compressed air and nitrogen (e.g. in the event of accident damage); no escape of refrigerant and no penetration of moisture and dirt into circuit
- Discharge refrigerant circuit.
- Replace restrictor.
- Remove receiver or reservoir.
- Remove dirt from receiver or reservoir.
- Weigh receiver or reservoir removed.

NOTE:
- Add refrigerant oil to new receiver or reservoir until weight of component removed has been attained.
- Install new receiver or reservoir.

- Assemble, evacuate and charge refrigerant circuit.