Page 1 of 26
MACS 609 CERTIFICATION 90 QUESTIONS WITH
CORRECT ANSWERS LATET UPDATE 2025/2026
The use of ultraviolet (UV) or fluorescent dyes in an HFO-1234yf
system is ......ANSWER........Approved by some vehicle
manufactures but not by others
One effect of some refrigerant gases in the atmosphere is that
they ......ANSWER........Contribute to trapping heat
Which item is not mentioned in the SAE J2099 Standard of
refrigerant purity? ......ANSWER........Sludge
When it has been determined that an A/C system has a low
refrigerant charge, what should be done?
......ANSWER........Perform a leak test procedure
Which item is not mentioned in the SAE J1991 standard of
refrigerant purity? ......ANSWER........Acid
Which of the following is unlikely to affect refrigerant charge
accuracy? ......ANSWER........A/C Compressor
CFC-12 recovery equipment has SAE 3/8-inch service fittings.
HFC-134a recovery equipment has ......ANSWER........Quick-
couple design
What is the advantage of using refrigerant identification
equipment? ......ANSWER........Allows the ability to determine what
type of refrigerant is in system
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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 ......ANSWER........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 ......ANSWER........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 ......ANSWER........Material safety data sheet (MSDS)
for the chemical
To what does Global Warming Potential (GWP) refer?
......ANSWER........Relative ability to produce global warming
effect
When performing engine pre-heat for refrigerant removal, the
technician should do ALL of the following EXCEPT
......ANSWER........Make sure the compressor is operating
PAG lubricant ......ANSWER........Is hygroscopic (absorbs moisture)
Electronic leak detectors certified to SAE J2791 have the
capability of identifying leakage rates as low as
......ANSWER........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 macyhine's gauges for a rise in pressure above
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vacuum, which would indicate that the system still contains some
refrigerant? ......ANSWER........5 minutes
A/C system service equipment hoses must be equipped with
shutoff valves located within _______ from the 'vehicle end' of
the hoses. ......ANSWER........12 inches
To what does Ozone Depletion Potential (ODP) refer?
......ANSWER........Relative ability to destroy ozone
Which type of tank must be used during the transfer of
refrigerant? ......ANSWER........Tanks marked DOT 4BA
When can HFC-134a become combustible in a mobile air
conditioning system? ......ANSWER........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? ......ANSWER........Answer: CFC-12
How much moisture is removed from a mobile A/C system during
a typical evacuation? ......ANSWER........Possibly none
When recovery/recycling equipment is used to remove
refrigerant from a mobile A/C system, how much lubricant will
be removed during the operation? ......ANSWER........Generally,
very little, if any
Mobile A/C system design changes, new service procedures and
equipment have been developed for what reason?
......ANSWER........To reduce lifetime refrigerant emissions
MACS 609 CERTIFICATION 90 QUESTIONS WITH
CORRECT ANSWERS LATET UPDATE 2025/2026
The use of ultraviolet (UV) or fluorescent dyes in an HFO-1234yf
system is ......ANSWER........Approved by some vehicle
manufactures but not by others
One effect of some refrigerant gases in the atmosphere is that
they ......ANSWER........Contribute to trapping heat
Which item is not mentioned in the SAE J2099 Standard of
refrigerant purity? ......ANSWER........Sludge
When it has been determined that an A/C system has a low
refrigerant charge, what should be done?
......ANSWER........Perform a leak test procedure
Which item is not mentioned in the SAE J1991 standard of
refrigerant purity? ......ANSWER........Acid
Which of the following is unlikely to affect refrigerant charge
accuracy? ......ANSWER........A/C Compressor
CFC-12 recovery equipment has SAE 3/8-inch service fittings.
HFC-134a recovery equipment has ......ANSWER........Quick-
couple design
What is the advantage of using refrigerant identification
equipment? ......ANSWER........Allows the ability to determine what
type of refrigerant is in system
,Page 2 of 26
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 ......ANSWER........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 ......ANSWER........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 ......ANSWER........Material safety data sheet (MSDS)
for the chemical
To what does Global Warming Potential (GWP) refer?
......ANSWER........Relative ability to produce global warming
effect
When performing engine pre-heat for refrigerant removal, the
technician should do ALL of the following EXCEPT
......ANSWER........Make sure the compressor is operating
PAG lubricant ......ANSWER........Is hygroscopic (absorbs moisture)
Electronic leak detectors certified to SAE J2791 have the
capability of identifying leakage rates as low as
......ANSWER........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 macyhine's gauges for a rise in pressure above
, Page 3 of 26
vacuum, which would indicate that the system still contains some
refrigerant? ......ANSWER........5 minutes
A/C system service equipment hoses must be equipped with
shutoff valves located within _______ from the 'vehicle end' of
the hoses. ......ANSWER........12 inches
To what does Ozone Depletion Potential (ODP) refer?
......ANSWER........Relative ability to destroy ozone
Which type of tank must be used during the transfer of
refrigerant? ......ANSWER........Tanks marked DOT 4BA
When can HFC-134a become combustible in a mobile air
conditioning system? ......ANSWER........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? ......ANSWER........Answer: CFC-12
How much moisture is removed from a mobile A/C system during
a typical evacuation? ......ANSWER........Possibly none
When recovery/recycling equipment is used to remove
refrigerant from a mobile A/C system, how much lubricant will
be removed during the operation? ......ANSWER........Generally,
very little, if any
Mobile A/C system design changes, new service procedures and
equipment have been developed for what reason?
......ANSWER........To reduce lifetime refrigerant emissions
