Refrigerant Gas Analysis, Performing
It is necessary for the operation of the A/C system that the refrigerant used has a certain purity.
Contamination with other refrigerants or gases can case damage and lead to failure of the A/C system.
Contaminated refrigerant must be returned to the gas supplier for processing (or disposal) as a gas of an unknown composition according to the legal requirements.
So that fluids components (for example drops of refrigerant oil) in the extracted refrigerant gas does not lead to a faulty result of the gas analysis, a separator (filter) is installed in the gas analyzer which separates the fluid drops. Replace the separator according to the specification of the gas analyzer for example the Owner's Manual belonging to the A/C service station. Refer to the Gas Analyzer Owner's Manual or Owner's Manual A/C service station.
All Vehicles
-- Connect the gas analyzer or the A/C service station according to the Owner's Manual and turn on. Refer to A/C SERVICE STATION ON REFRIGERANT CIRCUIT, CONNECTING , the Gas Analyzer Owner's Manual and/or the A/C service station Owner's Manual.
-- Perform the gas analysis according to the Owner's Manual. Refer to the A/C service station Owner's Manual.
Faulty gas analysis is possible due to air in the refrigerant hose or not following the procedure of the gas analysis according to the Owner's Manual.
A specific refrigerant circuit pressure is necessary (for example 2.5 bar (36.25 psi) at an ambient temperature of 20 °C (68 °F)) for performing the gas analysis. If there is only so little refrigerant in the circuit, so that not enough pressure is built (for example less than 30 g (1.05 oz) refrigerant which only builds a pressure of approximately 1 bar (14.5 psi)) depending on the version of the A/C Service Station it may be the case that a gas analysis can no longer be performed. Without a gas analysis no refrigerant may be removed from the A/C Service Station. If this is the case pay attention to the instructions in the Owner's Manual from the A/C Service Station. It is described what the quantity that is removed from the refrigerant circuit.
Pay exact attention to the gas analyzer/A/C service station Owner's Manual.
Evacuate the refrigerant hose from the A/C service station before connecting the service couplings to the refrigerant circuit/on the gas bottle with refrigerant R1234yf. Refer to the gas analyzer/A/C service station Owner's Manual.
The following results are possible for the gas analysis:
- If the analyzed refrigerant R1234yf meets the requirements, the planed procedures can be performed using the A/C service station.
- If a malfunction occurs during the gas analysis, determine the malfunction and correct it and the perform the gas analysis again. Refer to the A/C service station Owner's Manual.
- If the analyzed refrigerant R1234yf does not meet the requirements, the analyzed refrigerant must be extracted as a gas of an unknown composition and for example returned to the gas supplier to be analyzed, processed or disposed of. Refer to RETURN OF CONTAMINATED REFRIGERANT R1234YF FOR ANALYSIS, PREPARATION OR DISPOSAL .
If during the analysis of the refrigerant which was extracted from a vehicle refrigerant circuit contamination is determined. A gas analysis can be performed on for example refrigerant from a delivered bottle by the gas supplier if assurance is wanted of the gas analysis.
Due to the required purity of the refrigerant R1234yf small amounts of surrounding air in the A/C service station filler hoses can cause a faulty result. For this reason in most the A/C service station a process is included, in which the gas analysis is repeated up to two times before and NOK result is displayed. Refer to the A/C service station Owner's Manual.
A simple function test of the gas analyzer can be performed for example with the surrounding air. (Service coupling from the refrigerant hose with which the gas analysis is performed is removed and the gas analysis is performed with the refrigerant hose open). For this test it must then be displayed the analyzed gas is NOK.
The procedures of the gas analysis are developed for motor vehicle workshops and does not state the complete composition of the refrigerant. This gas analysis can only give the result of how high the portion of refrigerant R1234yf in the analyzed refrigerant is. If the portion or R1234yf is under 95% the refrigerant no longer meets the requirements and can cause damage to the refrigerant circuit components. A gas analysis which can give the exact composition of the analyzed refrigerant is currently not possible for the workshop area. Gas analysis which can determine the exact composition of gases require expensive devices and procedures and can usually only be preformed in test equipment for this.
If Contaminated Refrigerant Is Determined during the Gas Analysis before Continuing Work Speak with the Customer and Inform Them of the Following:
In the refrigerant circuit of their vehicle there is contaminated refrigerant or refrigerant of an unknown composition which does not meet the requirements of the vehicle manufacturer. This refrigerant:
- Must be extracted as a gas of an unknown composition and for example returned to the gas supplier to be analyzed, processed (or disposed of). Refer to RETURN OF CONTAMINATED REFRIGERANT R1234YF FOR ANALYSIS, PREPARATION OR DISPOSAL .
- Can be the cause of a malfunction or have damaged the refrigerant circuit to such an extent that in the near future malfunctions can occur.
- Depending on their composition the use of contaminated refrigerant can void the type approval of the vehicle.
- If internal damage to the refrigerant circuit occurs due to contaminated refrigerant (for example when a decomposition product of the contaminated refrigerant attacks the refrigerant circuit components, the refrigerant circuit can only be 100% serviced when all components which have touched the contaminated refrigerant have been replaced. The internal state of the refrigerant circuit can be evaluated by a visual inspection of specific refrigerant circuit components (for example the state of the inner surface of removed refrigerant lines and refrigerant hose, the inner surface of the receiver/dryer and the state of the removed dryer cartridge). Refer to COMPONENTS, REPLACING .
- If internal damage of the refrigerant circuit occurs due to contaminated refrigerant (for example A/C compressor failure due to damaged components or due to overheating, the refrigerant oil is discolored more than normal and the refrigerant carrying components however were not damaged the refrigerant circuit can be refilled after it is flushed (replaced A/C compressor, dryer and expansion valve). Because no statement/results about the long-term effect of contaminated refrigerant on the refrigerant oil and the refrigerant circuit components can be made, in this case no guarantee of the future function of the refrigerant circuit components is possible. Refer to COMPONENTS, REPLACING .
- If internal damage of the refrigerant circuit occurs due to contaminated refrigerant (for example the refrigerant oil is discolored more than normal and the refrigerant circuit components were not damaged) the refrigerant circuit can be refilled after the dryer is replaced and the refrigerant circuit is evacuated for a long time (minimum one hour). Because no statement/results about the long-term effect of contaminated refrigerant on the refrigerant oil and the refrigerant circuit components can be made, in this case no guarantee of the future function of the refrigerant circuit components is possible. Refer to COMPONENTS, REPLACING .
If there is a concern which was caused by contaminated refrigerant (for example leaking seals or hoses, a damaged A/C compressor, contaminated refrigerant) flush the refrigerant circuit and replace all components which the contaminated refrigerant has damaged (seals, hoses, the receiver/dryer or the dryer cartridge, the expansion valve and the A/C compressor). If it is determined that contaminated refrigerant has also damaged other components (for example the inner surfaces of the refrigerant pipes and refrigerant hoses, damaged seals) the refrigerant circuit must be completely replaced. Connect the refrigerant circuit and refill with new refrigerant. Then check the A/C system function. Make the customer aware for their protection that the refrigerant circuit was filled with contaminated refrigerant.
If there is a complaint which was caused by contaminated refrigerant (for example no or too little cooling output) and no other concerns on the refrigerant circuit can be determined or the refrigerant must be extracted because work in the refrigerant circuit surrounding area requires this, after extracting proceed as follows. Remove the dryer and check it for contamination, because refrigerant oil is located also on and in the dryer is must be checked. If the refrigerant oil is contaminated, dark or viscous or dirt deposits have built on the dryer, flush the refrigerant circuit and replace the components as described above (they may already be damages which can cause the refrigerant circuit to fail in the near future). If the refrigerant oil is OK and the dryer does not have more contamination than from normal operation, replace the dryer. Evacuate the refrigerant circuit longer than normally required (minimum one hour) and then fill with clean refrigerant. Check the A/C system function. Make the customer aware for their protection that the refrigerant circuit was filled with contaminated refrigerant.