On the wife's car. 2007 Mazda 6 2.3L. Been chasing a freon leak for a while. Last time I charged it, I put dye in it to hopefully pinpoint the culprit. Around the expansion valve = clean. All around the compressor = clean. The service connections = clean. Every point where's there's a connection with an o-ring = clean. However, the hose on the high pressure side is coated with gunk. I noticed yeaterday while I was changing the oil/filter which puts this otherwise hidden hose in your face under the car. It's as if there's an oily substance catching and accumulating the road grime. It's not just a small area, it's 80% of the hose. Do these things fail in such a way that coolant/oil seep through the lining?