In April of 2003, the a/c compressor and dryer were replaced and the system was retrofitted to R134a from R12. The a/c worked fine until this month of August (4.5 months later). Without warning the a/c stopped blowing cold air. I took the car back to the a/c specialist and found no gas in the system. Through a process of elimination, a leak in the system caused the complete lost of gas (2.2 lbs) from the previous repair, the specialist said. While there was no evidence of leak in the visible external component of the system (i.e., hoses, dryer, compressor, condenser), the specialist thinks that the leak is in the internal component of the system (i.e. evaporator). However, to confirm that the evaporator is the problem, the dash has to be removed for access and the estimated billable labor time is 18.5 hours plus parts. Yikes! Is the labor time period correct? Any suggestion?

Find a more experienced and better equipped automotive a/c "specialist."

An experienced and skillful a/c tech will find a way to thoroughly test for leaks WITHOUT doing such exploratory surgery. There are many different leak finding methods including UV dye and less common but maybe most effective is charging with a few ounces of R22 and dry nitrogen. R22 is more easily detected by an electronic leak detector.

18.5 hours is a lot of labor money to spend on an experiment.

Good luck,

I agree. Thanks for the tip.