Checking evaporator for leaks?

Does anyone know an easy way to check the evaporator for leaks that does not involve ripping the dash apart? I understand that I'd have to do this to replace the evaporator, but is there an easy way to push some dye in and visually inspect the core for leaks before I go through the trouble of taking everything apart? I've inspected the external components (lines, compressor, etc.) and can't find any trace of dye so am assuming it's the evaporator but would really hate to pull the dash and find no leaks in the evaporator.

Thanks in advance for any suggestions.

The way i always check the front evaporators is by looking at the drain tube for it. If it is leaking more than likely there will be a trace of dye around the tube or the area the water runs down the underside of the car. When the evaporator sweats the water runs down the evaporator and runs out the tube usually taking dye with it.