Components Of Refrigerant Circuit, Replacing

Components Of Refrigerant Circuit, Replacing

- All components of the refrigerant circuit submitted for quality observation are always to be sealed (use original sealing caps of replacement part).
- To date, the replacement parts "compressor, reservoir, receiver, evaporator and condenser" have been filled with nitrogen gas. This charge is being gradually discontinued/the pressure of the nitrogen charge is now so low that escape of gas is no longer perceptible on initial opening.
- On vehicles equipped with a compressor with no A/C clutch, the engine is only to be started following complete assembly of the refrigerant circuit (compressor always in operation as well).
- When the refrigerant circuit is empty, the compressor with A/C Compressor Regulator Valve N280 (without A/C clutch) is switched to internal lubrication with the result that only a minimal amount of oil is pumped from the compressor into the circuit.

NOTE:
- As parts are sometimes stored for lengthy periods and at different locations within the spare parts organization, it is entirely possible that gas will escape from some parts and not from others on initial opening (even in the case of identical spare part numbers). Sealing caps at replacement part connections are therefore to be removed carefully and the nitrogen gas allowed to escape slowly.
- The refrigerant circuit is equipped either with a restrictor and reservoir or an expansion valve and receiver.
- Components with desiccant bag (reservoir, receiver) are always to be replaced after flushing refrigerant circuit; in doing so, leave sealed as long as possible to minimize absorption of moisture.
- Components with desiccant bag (reservoir, receiver) are to be replaced if required for certain repair operations or if the refrigerant circuit has been open for a lengthy period and moisture has penetrated (e.g. following an accident).
- The period of time for which a refrigerant circuit may be left open without having to replace a component with desiccant bag (reservoir, receiver) is largely governed by ambient influences. Given a high ambient temperature and a high humidity level or if the vehicle has been standing in the open for example or driven (in wet, foggy weather conditions), the period will be considerably shorter than for a vehicle which has been standing in a heated dry area. The size of the opening through which moisture may ingress into the circuit also influences the period for which a refrigerant circuit can be left open without having to replace components with desiccant bag .
- Seal open connections and pipes (to prevent absorption of moisture).
- Always replace restrictor.

CAUTION:
- Contaminated refrigerant oils are to be disposed of as used oils of unknown origin.
- Audi-ServiceNet, Handbooks, HSO Environment 2

Components (except compressor, reservoir or receiver) leaking or damaged, refrigerant circuit completely empty

NOTE:
- In the event of only a minor leak with slow escape of refrigerant (e.g. at a small leakage point), the amount of refrigerant oil lost and the amount of moisture penetrating is not sufficient to influence operation of the air conditioner.
- The operations marked * are only to be implemented in the case of a major leak (e.g. following an accident).

- Remove malfunctioning component.
- Remove compressor.*
- Remove oil drain plug from compressor.*

NOTE:
- The oil drain plug of "Denso" and "Nippondenso" compressors is equipped with an oil seal instead of an O-ring and this is always to be replaced.
- To accelerate drainage of refrigerant oil, rotate compressor by way of clutch plate of A/C clutch for example.
- To accelerate drainage of refrigerant oil, rotate compressor by way of clutch plate of A/C clutch for example.
- Then fill compressor with quantity of fresh refrigerant oil corresponding to quantity of refrigerant oil in replacement compressor.
- 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.
- Cleaning (flushing) refrigerant circuit with compressed air or nitrogen.

- Replace receiver* or reservoir* and restrictor.
- Assemble, evacuate and re-charge refrigerant circuit Parts List.

Components (except compressor, reservoir or receiver) leaking or damaged, refrigerant circuit still containing refrigerant
- Discharge refrigerant circuit.
- Remove malfunctioning component, flush with compressed air and collect escaping refrigerant oil.
- The new component is to be filled with the amount of refrigerant oil flushed out (plus 20 cu.cm for evaporator, plus 10 cu.cm for condenser, refrigerant pipes and refrigerant hoses) as fresh refrigerant oil fill.

NOTE: Disposal of old refrigerant Audi-ServiceNet, Handbooks, HSO Environment 2.

- Replace restrictor.
- Assemble, evacuate and charge refrigerant circuit.

Compressor, replacing without the need for flushing refrigerant circuit with compressed air and nitrogen (e.g. in the event of external damage following an accident)
- Discharge refrigerant circuit.
- Remove compressor.
- Remove oil drain plug from compressor.

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

Parts List
- To accelerate drainage of refrigerant oil, rotate compressor by way of clutch plate of A/C clutch for example.
- Pour old refrigerant oil out of compressor (disposal Audi-ServiceNet, Handbooks, HSO Environment 2).
- Remove oil drain plug from replacement compressor, pour out refrigerant oil and only add a quantity of fresh refrigerant oil equal to the amount poured out of the malfunctioning compressor.

NOTE:
- If, for example, 70 cu.cm of refrigerant oil has been poured out of the malfunctioning compressor and 220 cu.cm out of the replacement compressor (a small quantity of refrigerant oil remains in the compressor), fill the compressor to be installed with 70 cu.cm of refrigerant oil (use can be made of oil poured out of replacement compressor).
- Use different refrigerant oils and quantities for the various compressors.
- If a greater quantity of refrigerant oil (more than approx. 80 cu.cm) has been poured out of the malfunctioning compressor, the remaining refrigerant oil can also be added to the evaporator or reservoir/receiver.

- Replace restrictor.
- Assemble, evacuate and charge refrigerant circuit.

Compressor, replacing on account of leakage or internal damage (e.g. noise or no output)
- Discharge refrigerant circuit.
- Remove compressor.

NOTE: In the event of internal (compressor) damage, check refrigerant hoses and condenser. If, e.g. swarf has penetrated, clean refrigerant hoses and condenser "Cleaning (flushing) refrigerant circuit with compressed air and nitrogen" and replace condenser if necessary.

- Replace receiver or reservoir and restrictor.
- Examine expansion valve for dirt or corrosion and replace if necessary.
- Assemble, evacuate and charge refrigerant circuit.

Receiver or reservoir and restrictor, 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 compressor.
- Rectify cause of trouble.
- Clean (flush) refrigerant circuit with compressed air and nitrogen.
- Examine expansion valve for dirt or corrosion and replace if necessary.
- Remove oil drain plug from compressor.

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

Parts List

- To accelerate drainage of refrigerant oil, rotate compressor by way of clutch plate of A/C clutch for example.
- Pour old refrigerant oil out of compressor.

NOTE: Disposal of old refrigerant Audi-ServiceNet, Handbooks, HSO Environment 2.

- 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.

Receiver or reservoir, 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 ingress 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.
- 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.