Air conditioning system servicing differences


There are some differences when it comes to servicing HFO-1234yf motor vehicle air conditioning systems, say officials at DuPont and the Mobile Air Conditioning Society (MACS) – the leading non-profit trade association for the mobile air conditioning, heating and engine cooling system segment of the automotive aftermarket (

New Recovery/Recycling/Recharging (RRR) equipment will be required due to the mild flammability of HFO-1234yf and other product differences. Some of the changes from R-134a equipment include new charge coupling and hoses; new unique tank fitting and tank color; new leak detection equipment; and air purge circuit calibration.

The officials warn that HFO1234yf refrigerant system components should not be replaced with ones removed from a system that uses another type of refrigerant, or from a salvaged vehicle.

Additional training for technicians using the new machines will likely be necessary. The U.S. EPA requires that motor vehicle air conditioning systems may only be serviced by technicians trained and certified by an EPA-approved technician training and certification program. Certification is required regardless of the refrigerant.



SAE International standards that apply to HFO-1234yf include:

- J2845, R-1234yf (HFO-1234yf) and R-744 Technician Training for Service and Containment of Refrigerants Used in Mobile A/C Systems.

- J2843, R-1234yf (HFO-1234yf) Recovery/Recycling/Recharging Equipment for Flammable Refrigerants for Mobile Air-Conditioning Systems.

- J2851, R-1234yf (HFO-1234yf) Refrigerant Recovery Equipment for Mobile Automotive Air-Conditioning Systems.

- J2844, R-1234yf (HFO-1234yf) New Refrigerant Purity and Container Requirements for Use in Mobile Air-Conditioning Systems.

- J2927, R-1234yf Refrigerant Identifier Installed In Recovery and Recycling Equipment for Use With Mobile A/C Systems.

- J2099, Standard of Purity for Recycled R-134a (HFC-134a) and R-1234yf (HFO-1234yf) for Use in Mobile Air-conditioning Systems.

- J2912, Performance Requirements for R-134a and R-1234yf Refrigerant Diagnostic Identifiers (RDI) for Use with Mobile Air Conditioning Systems.

SAE ( is a global association of engineers and related technical experts in the aerospace, automotive and commercial vehicle industries. Its SAE Standards are the workhorse documents that harmonize processes, practices and products throughout the mobility industry.