I bought my 300cd a decade or so ago, and I knew it had some history of AC leaks. I have all the receipts for the life of the car.
But it was still R-12 and it blew cold when I bought it, and any leakage was slow enough that for the three or so years that I used it before kids, I never added any. Then the car sat for ~6 years. And there was no pressure at all in the hoses.
I’ve been slowly getting the car back going again, doing some updates that I had meant to do, and others that have popped up. It was nice and cool until recently - now heat is here. So I wanted to troubleshoot. I don’t have bone dry nitrogen or R-22 for troubleshooting, but I could get some ES-12a for off road troubleshooting. I also got dye. So I installed this, and have run it a few hours. That stuff really does work well btw.
I wanted to pull my blower to lube the bushings, and to see if there was any sign of leakage via I’ve or my bc sniffer. I had been unsuccessful seeing any leaks, even at the R-4 compressor clutch and ports. But when I pulled the kick panel, I saw this:
After I pulled the blower, I saw this:
I’m guessing it’s just a bad o-ring, and the leaking refrigerant takes oil with it. Nothing under the kick panel is particularly oily. The noise insulation has some on it, but it isn’t sopping wet or something. I guess the time without r-12 and oil on the seal caused it to dry and crack.
So what is the best O-ring type and manufacturer for R-12? Ultimately I intend to go back to using that, once any leaks are found and fixed. And it seems best to start with this one...