MACS 609 CERTIFICATION Questions with
Detailed Verified Answers
The use of ultraviolet (UV) or fluorescent dyes in an HFO-1234yf system is: Ans:
Approved by some vehicle manufactures but not by others
One effect of some refrigerant gases in the atmosphere is that they: Ans: Contribute
to trapping heat
Which item is not mentioned in the SAE J2099 Standard of refrigerant purity? Ans:
Sludge
When it has been determined that an A/C system has a low refrigerant charge, what
should be done? Ans: Perform a leak test procedure
Which item is not mentioned in the SAE J1991 standard of refrigerant purity? Ans:
Acid
Which of the following is unlikely to affect refrigerant charge accuracy? Ans: A/C
Compressor
CFC-12 recovery equipment has SAE 3/8-inch service fittings. HFC-134a recovery
equipment has: Ans: Quick-couple design
What is the advantage of using refrigerant identification equipment? Ans: Allows the
ability to determine what type of refrigerant is in system
If an HFC-134a A/C system still has pressure after the first refrigerant recovery
process is complete (including the five-minute pause), additional recovery is necessary
until the system vacuum level remains stable for: Ans: 2 minutes
Paid technicians who service or repair buses using HCFC-22 as refrigerant, and/or
service or repair aircraft or ship/boat cargo refrigeration equipment: Ans: Must be
Section 608 Type II Certified
, Specific safety information for managing incidents involving refrigerants and other
chemicals (inhalation, spills, fires, etc.) is found in the: Ans: Material safety data sheet
(MSDS) for the chemical
To what does Global Warming Potential (GWP) refer? Ans: Relative ability to
produce global warming effect
When performing engine pre-heat for refrigerant removal, the technician should do
ALL of the following EXCEPT: Ans: Make sure the compressor is operating
PAG lubricant: Ans: Is hygroscopic (absorbs moisture)
Electronic leak detectors certified to SAE J2791 have the capability of identifying
leakage rates as low as: Ans: 0.15 ounce (4 grams) per year
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, which would indicate that the system still contains some
refrigerant? Ans: 5 minutes
A/C system service equipment hoses must be equipped with shutoff valves located
within _______ from the "vehicle end" of the hoses. Ans: 12 inches
To what does Ozone Depletion Potential (ODP) refer? Ans: Relative ability to destroy
ozone
Which type of tank must be used during the transfer of refrigerant? Ans: Tanks
marked DOT 4BA
When can HFC-134a become combustible in a mobile air conditioning system? Ans: If
shop air is used in the system in an attempt to check for leaks and HFC-134a is
present
Mineral-based lubricants are used in which type of mobile A/C system? Ans: CFC-12
© Get it right 2025 Getaway - Stuvia US All rights reserved
Detailed Verified Answers
The use of ultraviolet (UV) or fluorescent dyes in an HFO-1234yf system is: Ans:
Approved by some vehicle manufactures but not by others
One effect of some refrigerant gases in the atmosphere is that they: Ans: Contribute
to trapping heat
Which item is not mentioned in the SAE J2099 Standard of refrigerant purity? Ans:
Sludge
When it has been determined that an A/C system has a low refrigerant charge, what
should be done? Ans: Perform a leak test procedure
Which item is not mentioned in the SAE J1991 standard of refrigerant purity? Ans:
Acid
Which of the following is unlikely to affect refrigerant charge accuracy? Ans: A/C
Compressor
CFC-12 recovery equipment has SAE 3/8-inch service fittings. HFC-134a recovery
equipment has: Ans: Quick-couple design
What is the advantage of using refrigerant identification equipment? Ans: Allows the
ability to determine what type of refrigerant is in system
If an HFC-134a A/C system still has pressure after the first refrigerant recovery
process is complete (including the five-minute pause), additional recovery is necessary
until the system vacuum level remains stable for: Ans: 2 minutes
Paid technicians who service or repair buses using HCFC-22 as refrigerant, and/or
service or repair aircraft or ship/boat cargo refrigeration equipment: Ans: Must be
Section 608 Type II Certified
, Specific safety information for managing incidents involving refrigerants and other
chemicals (inhalation, spills, fires, etc.) is found in the: Ans: Material safety data sheet
(MSDS) for the chemical
To what does Global Warming Potential (GWP) refer? Ans: Relative ability to
produce global warming effect
When performing engine pre-heat for refrigerant removal, the technician should do
ALL of the following EXCEPT: Ans: Make sure the compressor is operating
PAG lubricant: Ans: Is hygroscopic (absorbs moisture)
Electronic leak detectors certified to SAE J2791 have the capability of identifying
leakage rates as low as: Ans: 0.15 ounce (4 grams) per year
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, which would indicate that the system still contains some
refrigerant? Ans: 5 minutes
A/C system service equipment hoses must be equipped with shutoff valves located
within _______ from the "vehicle end" of the hoses. Ans: 12 inches
To what does Ozone Depletion Potential (ODP) refer? Ans: Relative ability to destroy
ozone
Which type of tank must be used during the transfer of refrigerant? Ans: Tanks
marked DOT 4BA
When can HFC-134a become combustible in a mobile air conditioning system? Ans: If
shop air is used in the system in an attempt to check for leaks and HFC-134a is
present
Mineral-based lubricants are used in which type of mobile A/C system? Ans: CFC-12
© Get it right 2025 Getaway - Stuvia US All rights reserved
