[Big Kev-O]

As an HVAC tech I always start with the good old fashioned method of using Big Blue or Cal-Blue leak detector. You spray or brush it onto the fitting and lines and watch for bubbles. You should be able to pick some up for around $10 at your local home improvement store, supply house and maybe auto parts store. The key with the spray bottle is to pull the trigger slowly so you don't create a bunch of bubbles. Brushing it on works even better. I have found some very slow leaks using this technique, this stuff blows some big bubbles. Dish soap will work on larger leaks but wont bubble up like the Big Blue. If I cannot find the leak with the bubble method i go to my electronic leak detector. If I cannot pinpoint it with the electronic detector then i use dye & UV light. Since most guys don't have the specialty tools I suggest starting with the bubble method. Good Luck!