I use a Javac Tek mate leak detector.

This is probably about an average type of leak detector.

One thing I notice about it is that it seems to have more trouble finding leaks with 404a and 134a than r12 and r22.I have once replaced the sensor in it when it had no sensitivity and it then functioned ok.

A few days ago I had a leak in an evaporator which I located with soapy water but the leak detector couldn't find it at all.(Refrigerant was 404a).

Do any other members have similar problems and does anyone have any suggestions of a leak detector that is equally sensative to all gasses.

Thanks in advance.