MACS 609 Certification Exam Questions
and Answers | Newest Updated Study
Guide with Accurate Solutions | Grade A+
• One effect of some refrigerant gases in the atmosphere is that they: -✓✓Contribute to
trapping heat
• Which item is not mentioned in the SAE J2099 Standard of refrigerant purity? -
✓✓Sludge
• When it has been determined that an A/C system has a low refrigerant charge, what
should be done? -✓✓Perform a leak test procedure
• Which item is not mentioned in the SAE J1991 standard of refrigerant purity? -✓✓Acid
• Which of the following is unlikely to affect refrigerant charge accuracy? -✓✓A/C
Compressor
• CFC-12 recovery equipment has SAE 3/8-inch service fittings. HFC-134a recovery
equipment has: -✓✓Quick-couple design
• What is the advantage of using refrigerant identification equipment? -✓✓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: -✓✓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: -✓✓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: -✓✓Material safety data sheet
(MSDS) for the chemical
• To what does Global Warming Potential (GWP) refer? -✓✓Relative ability to produce
global warming effect
• When performing engine pre-heat for refrigerant removal, the technician should do
ALL of the following EXCEPT: -✓✓Make sure the compressor is operating
, • PAG lubricant: -✓✓Is hygroscopic (absorbs moisture)
• Electronic leak detectors certified to SAE J2791 have the capability of identifying
leakage rates as low as: -✓✓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? -✓✓5 minutes
• A/C system service equipment hoses must be equipped with shutoff valves located
within _______ from the "vehicle end" of the hoses. -✓✓12 inches
• To what does Ozone Depletion Potential (ODP) refer? -✓✓Relative ability to destroy
ozone
• Which type of tank must be used during the transfer of refrigerant? -✓✓Tanks marked
DOT 4BA
• 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
• Mineral-based lubricants are used in which type of mobile A/C system? -✓✓CFC-12
• How much moisture is removed from a mobile A/C system during a typical
evacuation? -✓✓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? -✓✓Generally, very
little, if any
• Mobile A/C system design changes, new service procedures and equipment have
been developed for what reason? -✓✓To reduce lifetime refrigerant emissions
• Why is it necessary to ensure that service port caps containing good seals are
installed? -✓✓To minimize refrigerant loss
• Which of the following is NOT a factor in how much refrigerant can be recovered from
an A/C system? -✓✓The age of the vehicle
• The U.S. EPA has classified HFO-1234yf as "Acceptable, subject to use conditions."
That means: -✓✓The refrigerant may only be used in newly manufactured vehicles with
components specifically designed for it
and Answers | Newest Updated Study
Guide with Accurate Solutions | Grade A+
• One effect of some refrigerant gases in the atmosphere is that they: -✓✓Contribute to
trapping heat
• Which item is not mentioned in the SAE J2099 Standard of refrigerant purity? -
✓✓Sludge
• When it has been determined that an A/C system has a low refrigerant charge, what
should be done? -✓✓Perform a leak test procedure
• Which item is not mentioned in the SAE J1991 standard of refrigerant purity? -✓✓Acid
• Which of the following is unlikely to affect refrigerant charge accuracy? -✓✓A/C
Compressor
• CFC-12 recovery equipment has SAE 3/8-inch service fittings. HFC-134a recovery
equipment has: -✓✓Quick-couple design
• What is the advantage of using refrigerant identification equipment? -✓✓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: -✓✓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: -✓✓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: -✓✓Material safety data sheet
(MSDS) for the chemical
• To what does Global Warming Potential (GWP) refer? -✓✓Relative ability to produce
global warming effect
• When performing engine pre-heat for refrigerant removal, the technician should do
ALL of the following EXCEPT: -✓✓Make sure the compressor is operating
, • PAG lubricant: -✓✓Is hygroscopic (absorbs moisture)
• Electronic leak detectors certified to SAE J2791 have the capability of identifying
leakage rates as low as: -✓✓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? -✓✓5 minutes
• A/C system service equipment hoses must be equipped with shutoff valves located
within _______ from the "vehicle end" of the hoses. -✓✓12 inches
• To what does Ozone Depletion Potential (ODP) refer? -✓✓Relative ability to destroy
ozone
• Which type of tank must be used during the transfer of refrigerant? -✓✓Tanks marked
DOT 4BA
• 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
• Mineral-based lubricants are used in which type of mobile A/C system? -✓✓CFC-12
• How much moisture is removed from a mobile A/C system during a typical
evacuation? -✓✓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? -✓✓Generally, very
little, if any
• Mobile A/C system design changes, new service procedures and equipment have
been developed for what reason? -✓✓To reduce lifetime refrigerant emissions
• Why is it necessary to ensure that service port caps containing good seals are
installed? -✓✓To minimize refrigerant loss
• Which of the following is NOT a factor in how much refrigerant can be recovered from
an A/C system? -✓✓The age of the vehicle
• The U.S. EPA has classified HFO-1234yf as "Acceptable, subject to use conditions."
That means: -✓✓The refrigerant may only be used in newly manufactured vehicles with
components specifically designed for it
