Using a new type of testing that better simulates real world conditions, where the refrigerant is dynamically dispersed at high pressure near to hot components of the exhaust system, such as during a head-on collision, researchers determined there was a chance the substance might ignite. The previous R134a refrigerant that R1234yf replaced was also tested and deemed safe.
In response to the finding, Mercedes-Benz is recalling all 2013 SL Class models manufactured from December 19, 2011, through May 31, 2012, which were originally equipped with R1234yf. According to the automaker, there are some 432 vehicles affected by the latest recall in the U.S.
Owners will be notified this month and asked to take their cars to their nearest Mercedes-Benz dealer, which will replace the R1234yf refrigerant with the older R134a substance along with new refrigerant hoses designed specifically for R134a.
For further information you can contact the National Highway Traffic Safety Administration's hotline at 1-888-327-4236 (reference recall campaign number 12V478000) or Mercedes-Benz at 1-800-367-6372.