Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector: Notes

Leaks on the R1234yf refrigerant circuit can only be determined using electronic leak detectors, which were designed for refrigerant R1234yf.

The various refrigerants have differing molecular compositions. The electronic leak detector sensors are set up to detect these molecules. If an electronic leak detector is used, which is not specifically designed to detect refrigerant R1234yf, it will not respond to the refrigerant R134a or will only do so when there is a larger concentration of refrigerant R1234yf in the area of the leak. For this reason electronic leak detectors which were only designed for refrigerant R134a cannot be used for leak detection on R1234yf refrigerant circuits.

Depending on the version of the heater and A/C unit, an evaporator leak can also be determined either by holding the leak detector test probe over the glove compartment cooling connection in the heater and A/C unit, or by holding the test probe on an open connection of a disconnected heater and A/C unit condensation water hose.

To prevent more refrigerant than is necessary for the leak test from venting into the air with the refrigerant circuit completely empty, proceed as follows:

If a larger leak is found during evacuation, find and it and repair it as described. Refer to REFRIGERANT CIRCUIT, EVACUATING .

If no leak is found during evacuation or there is a leak that is so small that the location cannot be found with the vacuum test, proceed as follows.