Podcast
Questions and Answers
If lubricant is removed by recovery equipment during system refrigerant removal, what must be done with the lubricant?
If lubricant is removed by recovery equipment during system refrigerant removal, what must be done with the lubricant?
Re-install lubricant removed by the recovery equipment
Before reuse, what must be done with HFC-134a that has been recovered from a mobile A/C system using recovery-only equipment?
Before reuse, what must be done with HFC-134a that has been recovered from a mobile A/C system using recovery-only equipment?
When can HFC-134a become combustible in a mobile air conditioning system?
When can HFC-134a become combustible in a mobile air conditioning system?
If shop air is used in the system in an attempt to check for leaks and HFC-134a is present
Which type of mobile A/C system will usually require additional time/precautions to extract all the refrigerant?
Which type of mobile A/C system will usually require additional time/precautions to extract all the refrigerant?
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Electronic leak detectors certified to SAE J2791 have the capacity of identifying leakage rates as low as:
Electronic leak detectors certified to SAE J2791 have the capacity of identifying leakage rates as low as:
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When recovery/recycling equipment is used to remove refrigerant from a mobile A/C system, how much lubricant will be removed during the operation?
When recovery/recycling equipment is used to remove refrigerant from a mobile A/C system, how much lubricant will be removed during the operation?
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Why is it necessary to ensure that service port caps containing good seals are installed?
Why is it necessary to ensure that service port caps containing good seals are installed?
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Which of the following statements is correct about flushing A/C systems?
Which of the following statements is correct about flushing A/C systems?
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When using an HFC-134a refrigerant recovery machine, after completing the first recovery process, how long must you wait, then check the machine's gauges for a rise in pressure above vacuum?
When using an HFC-134a refrigerant recovery machine, after completing the first recovery process, how long must you wait, then check the machine's gauges for a rise in pressure above vacuum?
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Which type of tank must be used during the transfer of refrigerant?
Which type of tank must be used during the transfer of refrigerant?
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When it has been determined that an A/C system has a low refrigerant charge, what should be done?
When it has been determined that an A/C system has a low refrigerant charge, what should be done?
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One effect of some refrigerant gases in the atmosphere is that they:
One effect of some refrigerant gases in the atmosphere is that they:
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Mixing CFC-12 and HFC-134a in the same system will:
Mixing CFC-12 and HFC-134a in the same system will:
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How much moisture is removed from a mobile A/C system during a typical evacuation?
How much moisture is removed from a mobile A/C system during a typical evacuation?
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Paid technicians who service or repair mobile A/C systems using HFC-22 as refrigerant, or service cargo refrigeration equipment:
Paid technicians who service or repair mobile A/C systems using HFC-22 as refrigerant, or service cargo refrigeration equipment:
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HFO-1234yf is classified as 'A2L-mildly flammable.' This means:
HFO-1234yf is classified as 'A2L-mildly flammable.' This means:
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Section 609 of the Clean Air Act requires that recovery/recycling equipment:
Section 609 of the Clean Air Act requires that recovery/recycling equipment:
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What is the advantage of using refrigerant identification equipment?
What is the advantage of using refrigerant identification equipment?
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When performing engine pre-heat for refrigerant removal, the technician should do ALL of the following EXCEPT:
When performing engine pre-heat for refrigerant removal, the technician should do ALL of the following EXCEPT:
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If a large amount of lubricant is removed from a system during refrigerant recovery:
If a large amount of lubricant is removed from a system during refrigerant recovery:
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PAG lubricant:
PAG lubricant:
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Specific safety information for managing incidents involving refrigerants and other chemicals (inhalation, spills, fires, etc) is found in the:
Specific safety information for managing incidents involving refrigerants and other chemicals (inhalation, spills, fires, etc) is found in the:
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What is not identified in the manual as a concern with field-coupled hoses?
What is not identified in the manual as a concern with field-coupled hoses?
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Which of the following is NOT a factor in how much refrigerant can be recovered from an A/C system?
Which of the following is NOT a factor in how much refrigerant can be recovered from an A/C system?
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HFO-1234yf can be used in:
HFO-1234yf can be used in:
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Study Notes
Refrigerant Recovery and Management
- Reinstall lubricant removed by recovery equipment during refrigerant removal.
- HFC-134a must be recycled before reuse using certified equipment.
- HFC-134a can become combustible if shop air is introduced while checking for leaks.
- Accumulator type mobile A/C systems require more time and precautions to extract refrigerant.
Leak Detection and Equipment
- Electronic leak detectors certified to SAE J2791 can identify leakage rates as low as 0.15 ounces per year.
- Recovery/recycling equipment generally removes very little to no lubricant from A/C systems.
- Service port caps with good seals are essential to minimize refrigerant loss.
A/C System Maintenance
- Flushing A/C systems can leave solvents behind, potentially causing problems.
- After the first recovery process with HFC-134a recovery machine, wait 5 minutes to check for pressure rise indicating remaining refrigerant.
- Tanks marked DOT 4BA must be used for refrigerant transfer.
Refrigerant Charge and Environmental Impact
- Perform leak detection if an A/C system has a low refrigerant charge.
- Certain refrigerant gases in the atmosphere contribute to heat trapping.
- Mixing CFC-12 and HFC-134a results in refrigerant cross contamination.
Moisture and Technician Certification
- A typical evacuation of a mobile A/C system may remove no moisture.
- Technicians servicing mobile A/C systems using HFC-22 must be Section 608 Type II certified.
Safety and Regulations
- HFO-1234yf is mildly flammable (A2L) and can ignite under certain conditions.
- Recovery/recycling equipment must be registered with the EPA under Section 609 of the Clean Air Act.
- Refrigerant identification equipment helps determine the type of refrigerant in the system.
Best Practices in Refrigerant Handling
- During engine pre-heat for refrigerant removal, do not ensure that the compressor is operating.
- A large amount of lubricant removal indicates the system likely had excessive lubricant.
- PAG lubricant is hygroscopic, meaning it absorbs moisture.
Chemical Safety and Equipment Concerns
- Specific safety information for refrigerants and chemicals is found in the Material Safety Data Sheet (MSDS).
- The length of field-coupled hoses is not identified as a concern in management manuals.
- The age of the vehicle is not a factor in how much refrigerant can be recovered from an A/C system.
Applications of HFO-1234yf
- HFO-1234yf can be used in any light vehicle with an A/C system specifically designed for it.
Studying That Suits You
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Description
Test your knowledge on refrigerant recovery and lubricant management with these flashcards for MACS 609 certification. Each card covers essential practices for handling HFC-134a and lubricants in A/C systems. Perfect for those preparing for MACS certification exams.
