A safe, fast and accurate method of detecting a leak locale of a stator liquid cooling system especially in a plurality of stator windings in a liquid cooled generator is provided. The method includes the step of introducing a non-corrosive compatible gas or its air mixture having an infrared absorption spectrum into the plurality of stator windings of the liquid cooled generator and detecting leaks through the use of an infrared detection system. The infrared detection system includes an imaging component adapted to detect radiation at the infrared absorption spectrum of the non-corrosive gas or its air mixture. The imaging component is provided with a filter that filters wavelengths in a range encompassing the infrared absorption spectrum of the compatible, non-corrosive gas. The imaging component displays an image of the tracer gas leaking from stator liquid cooling system of the generator.