Review on OEMTOOLS 24561 R134a to HFO-1234YF Conversion Coupler Set - 1 Pack by Evan Martinez

These fittings do exactly what they are advertised for, allowing the use of R134 14mm threaded hoses (and gauge manifold) with R1234yf automotive fittings. Real R1234yf hoses have 12mm threads instead. With the supplied tank adapter you can use the yellow R134 filling hose with the left-hand thread of R1234yf tanks. REVISION 2017-07-20: The 14mm threads on the hoses have an o-ring that seals the bottom, part of the female thread on the coupler; The mechanical thread stop must be the hex of the fitting's female threads against the hex of the hose's male threads. The pad on the couplers is TOO short and while it is enough to seal the o-ring, the mechanical stop occurs between the hose o-ring and the first thread in the coupler. :( I've attached an image showing the Air Products coupler and the coupler offered here. If you use R134 gauges you will need a PT chart or PT chart app for your phone so you can read temps You can also replace the pressure gauges on your manifold with pressure gauges with both temperature scales