The new R-1234yf refrigerant is more than just a new jumble of numbers and letters on a label. For your shop, R-1234yf means several new procedures, a certification and new equipment in order to properly handle these new systems.
Why the difference in handling and servicing R-1234yf systems versus R-134a? The reason is flammability. Don’t be alarmed, because R-1234yf isn’t extremely flammable by any stretch, but its mild flammability carries more risks and requires additional safe-handling procedures.
Technicians are being recommended to recertify under the SAE standard J609 Technician Training Certification Program. This training standard has been updated with new precautions and instructions to ensure that technicians understand the handling and servicing of the new R-1234yf refrigerant. J2845 also contains valuable information for the service and containment of R-1234yf refrigerant used in mobile A/C systems.
Many diagnostic procedures are the same as before, but there are additional steps that have been tacked on to account for the proper handling of the mildly flammable R-1234yf. Several of these safety checks might be automatically and semi-automatically performed by a new service machine, such as ensuring proper refrigerant type and testing the system for leaks, but they all add extra time to the overall service interval.
First, a refrigerant identification must be performed with a refrigerant identifier.
Connect the identifier per manufacturer instructions and allow it to calibrate. Some identifiers will give a pass/fail grade, while others will report the percentages of chemicals within the system. Identifiers that meet the SAE specification will be calibrated to read 98% concentration as “pure.”
Prior to charging a vehicle, the machine must perform two system tests to ensure the vehicle A/C system is sealed before recharging takes place.
First, the machine will run a vacuum decay leak check. If the slope of the vacuum decay exceeds 51 mm Hg/min in five minutes, a leak is indicated, and a technician must locate and repair the leaks before recharge can continue. In the case of a repair, remember to order the correct repair parts. Evaporators and other components R-1234yf systems use are not the same as those used with R-134a.
After the vacuum test comes a partial pressurization and pressure decay leak test. The machine will instruct the technician to turn the HVAC blower motor on low, with distribution set to floor. After two minutes, a leak detector probe set for maximum sensitivity is placed in the center of a floor duct. From there, the machine charges the system with 15% of the total refrigerant in the high and low sides while the technician monitors the leak detector. If no leak is detected after five minutes, the rest of the refrigerant is charged.
R-1234yf systems use less refrigerant than older systems and are tuned to a specific amount. An undercharge will result in poor cooling or lubrication circulation, and an overcharge could cause high operating pressures and poor cooling.
There is no backward compatibility when it comes to refrigerants, and that goes for the recovery/recycle/recharge machines as well. In fact, by law, when a refrigerant is updated, a system’s ports must change in size, shape and thread pattern as well to specifically make previous machines incompatible with the new systems and to avoid accidentally using the incorrect refrigerant. So, in order to work on these new A/C systems, you will need new equipment.
Recovery/recycle/recharge machines. New recovery/recycle/recharge machines have many upgrades that ensure the safe handling of R-1234yf and check for leakage in the system. As noted earlier, several of these safety features, such as the vacuum and pressure tests, will increase the overall service timeframe. New labeling is required on these machines that provide further instructions and cautionary statements needed for the service.
The new machines will include multiple designated fresh air intakes and strategically located ventilation drain areas if an internal release of R-1234yf occurs. Some will monitor the internal ventilation fan for a minimum of six air changes per hour and will lock out operation should this minimum flow rate fail. On-board oil injection is not allowed with the new R-1234yf equipment and must be performed using manual oil injectors.
Refrigerant identifiers. You will also need a new refrigerant identifier (some recovery machines come equipped with one). The role of the identifier in A/C service has only increased in importance with R-1234yf. Mixing refrigerants can lead to system pressure issues, component damage, diagnostic errors and environmental or personal harm.
Any new r/r/r machine must meet SAE J2843 requirements; recovery-only units must meet SAE J2851. The r/r/r unit must either come equipped with an integrated J2927-compliant refrigerant identifier or must be capable of receiving information from a J2912-compliant identifier via a USB port.
Leak detectors. Shops servicing R-1234yf must also invest in an electronic leak detector that is SAE J2913-certified to adequately detect refrigerant leaks. New hoses, couplers and fittings are required as well that meet the J2888 standard. Any dye being added to the system must be J2297-certified in order to be sure it is compatible with the refrigerant and will not harm seals or lubricants.
For salvage yards and other shops that strictly reclaim refrigerants, they must invest in a recovery-only machine that is certified to meet J2851.
Vehicles now equipped with R-1234yf
Vehicles equipped with R-1234yf just started to hit the road in 2014, and it might be another few years before they enter your bays in a significant number. But before you know it, this will be the new norm. Here is the most up-to-date list of vehicles currently equipped with R-1234yf in the U.S.
BMW I3 and I8
Chevrolet Spark EV
Honda Fit EV
Jeep CherokeeDodge Dart
Tesla Model S
More vehicles will be added to the U.S. list in 2015 including models from Honda and Toyota. Here is the list that’s currently available outside the U.S.:
BMW i3 Electric,
Cadillac XTS (2013 and 2014),
Chevrolet Spark EV (2014),
Chrysler 300 (2014),
Dodge Challenger (2014),
Honda Fit EV (2013 and 2014),
Hyundai Santa Fe, i30
Jeep Cherokee (2014),
Kia Sorento, Optima, Carenz,
Peugeot 301, 308,
Range Rover and Range Rover Sport (2014),
Subaru BRZ, Forrester, Impreza.