Re: Wheres the Evaporator Core?
i worked on auto A/C exclusively for 12 years. Unless you've actually SEEN these components leaking, don't believe it. The compressor,yeah, it's possible, but in my experience, it's normally the shaft seal (inexpensive part) in the compressor which is quite easily replaced with proper tools.
I'd bet the farm that your evaporator is NOT leaking.
In my experience, what these mechanics will do is diagnose a couple of very expensive parts, then if replacing them doesn't fix it, they've got a little "pad" to work with. Remember, R134A is relatively cheap, so unless you have a huge leak, get a set of gauges and learn how to recharge your system. Also, if you do have a very large leak, the most effective leak finding tool is a mixture of water and clear (MUST be clear...any color, but clear) dishwashing soap. Just squirt the mix on your A/C components and it'll bubble like mad wherever it's leaking. I've used this stuff with more success than $500 electronic leak detectors. Of course you can't check the evap. as it's uinder the dash, but it's highly doubtful that it's leaking. Also, typically where refrigerant leaks, so does refrigeration oil, and of course dirt sticks to oil, so look for dirty or oily areas on and around your system.