Replacing Components
A/C Refrigerant System, Replacing Components
Replacement A/C compressors, evaporators and condensers supplied by the Parts Department are filled with Nitrogen. If gas (Nitrogen) does not escape when the component is first opened, the component may be faulty (leaking) and must not be installed.
Replacement A/C compressors are filled with the total refrigerant oil quantity needed for the entire refrigerant system.
Always replace the receiver drier whenever the refrigerant system has been left open. Install immediately after opening to prevent moisture contamination of drier desiccant. Moreover, keep refrigerant system and other replacement components sealed for as long as possible to minimize the chance of dirt and moisture contamination.
Always plug open refrigerant line connections to prevent dirt and moisture contamination.
If the system has been discharged because of a damaged or leaking component (refrigerant hose/line, compressor, evaporator, condenser, etc.), flush the refrigerant system first with compressed air, then with Nitrogen (available locally) and collect the oil that runs out. This will remove the refrigerant oil which may be saturated with moisture.
CAUTION! DO NOT flush R-134a refrigerant system with R-11. R-11 is not compatible with refrigerant R134a and PAG oil and will cause total system contamination.
If the compressor is not replaced after flushing the system, fill compressor with the correct type and quantity of refrigerant oil specified under A/C system capacities. Fill compressor with the total system oil capacity.
If the compressor is replaced, do not add additional oil as the total amount of oil required is already in the compressor.
Dispose of contaminated refrigerant oil following laws governing hazardous waste disposal. Do not combine any refrigerant oil with any other old oils such as engine oil or transmission fluid.
Follow all applicable Warnings and Cautions when working on the A/C system.
For leaking or damaged components (except for compressor and receiver drier), A/C system was completely empty (no charge):
- Remove malfunctioning component.
- Remove compressor.
- Remove oil drain plug from compressor.
NOTE:
- Rotate compressor manually to speed up oil draining process.
- The compressor oil drain plug O-ring has been replaced with a sealing ring (always replace).
- Drain old refrigerant oil out of compressor into a measuring container. Record volume of refrigerant oil drained.
- Subsequently, fill compressor with new refrigerant oil equal to the amount of oil drained in previous step.
NOTE:
- Fill amounts for refrigerant oil.
- To ensure adequate compressor lubrication, add at least 80 cm(3) (2.7 oz) of refrigerant oil into compressor, the remainder can be added to new receiver drier.
- If there is dirt in the compressor of an open A/C system (e.g. during an accident), replace compressor.
- Blow through circuit with compressed air and nitrogen.
- Replace receiver drier.
- Assemble A/C system, evacuate and recharge.
For leaky or damaged components (except for the compressor and receiver drier) there is still refrigerant in the A/C system:
- Discharge A/C system.
- Remove malfunctioning component, blow through with compressed air, collect all exhausted oil in a measuring container.
Refrigerant oil amount blown out of system, plus 20 cm(3) (0.7 oz) in evaporator, plus 10 cm(3) (0.3 oz) from condenser, refrigerant lines and hoses, is replaced as new refrigerant oil amount in the new component.
- Assemble A/C system, evacuate and recharge.
Replace compressor, without it being necessary to blow through the refrigerant system with compressed air and nitrogen (e.g. exterior damage after an accident):
- Discharge A/C system.
- Remove damaged compressor.
- Remove oil drain plug from compressor.
- Drain old refrigerant oil out of malfunctioning compressor into a measuring container. Record volume of drained refrigerant oil.
NOTE:
- Rotate compressor manually to speed up oil draining process.
- The compressor oil drain plug O-ring has been replaced with a sealing ring (always replace).
- Drain refrigerant oil also out of replacement compressor into a clean container. Refill replacement compressor with amount of fresh oil equal to the amount poured out of malfunctioning compressor.
Example:
From the malfunctioning compressor only 70 cm(3) (2.4 oz) of refrigerant oil was poured out. From the replacement compressor 220 cm(3) of refrigerant oil poured out (a small amount remains in compressor). 70 cm(3) (2.4 oz) of refrigerant oil needs to be poured back into replacement compressor (oil originally from replacement compressor, held in clean container).
NOTE: If a larger amount of refrigerant oil poured out of the malfunctioning compressor, more than approx. 80 cm(3) (2.7 oz) the remaining refrigerant oil can be used for the condenser or receiver drier.
- Assemble A/C system, evacuate and recharge.
Replace compressor due to leaks or internal damage (e.g. noises or no power):
- Discharge A/C system.
- Remove compressor.
NOTE:
- If there is internal damage (to compressor), check refrigerant hoses.
- If metal pieces are found to be embedded, replace hose.
- Blow through A/C system with compressed air and nitrogen.
- Replace receiver drier and expansion valve.
- Assemble A/C system, evacuate and charge.
Replace receiver drier after blowing through the A/C system e.g. caused by moisture contamination (the A/C system was open over a long period of time) or contamination (dirt):
- Discharge A/C system.
- Remove compressor.
- Eliminate cause of malfunction.
- Blow through A/C system with compressed air and nitrogen.
- Remove and check expansion valve for blockage/dirt and corrosion. Replace if necessary.
- Remove oil drain plug out of compressor.
- Drain and measure old refrigerant oil from compressor.
NOTE: Rotate compressor manually to speed up oil draining process.
- Record volume of refrigerant oil drained.
- Fill compressor with new refrigerant oil: the amount of oil must be equal to amount of old refrigerant oil drained.
NOTE:
- Fill amounts for refrigerant oil.
- To ensure adequate compressor lubrication, add at least 80 cm(3) (2.7 oz) of refrigerant oil into compressor. The remainder can be added to new receiver drier.
- If there is dirt in the compressor of an open A/C system (e.g. during an accident), replace compressor.
- Blow through A/C circuit with compressed air and nitrogen.
- Replace receiver drier.
- Assemble A/C system, evacuate and charge.
Replace receiver drier, without it being necessary to blow through A/C system with compressed air and nitrogen (e.g. damage caused by an accident), no refrigerant flowed out and no moisture and dirt have penetrated the circuit:
- Discharge A/C system.
- Remove receiver drier.
- Clean outside housing of receiver drier.
- Weigh removed receiver drier.
- Fill new receiver drier with new refrigerant oil until it weighs as much as removed receiver drier.
- Install receiver drier.
- Assemble A/C system, evacuate and recharge.