refridgerant dye is a good way for slow leaks in visible area's and a great way to get the tech. on to the next job, but there are components difficult to access visually even with a 'black llight' borescope which i use to pin point some oil leaks. Most leaks will show up with an electronic leak detector if used correctly. Expect to replace to rec./drier and a hose, but get a second opinion if it gets expensive! the dye & R134 will still be in the system, you did pay for it. best of luck ! jb