I was wondering if it actually possible to see an AC leak by eye. Say one of the aluminum pipes were to leak, would you be able to see a specific type of discoloration caused by the refrigerant around the leaky area?
The reason I am asking that is because I have a leak in my AC (actually had it for a couple of years) and I decided to finally fix it.
I do have a sniffer, but considering the system is completely empty, I don't think I will be able to find the leak that way. I do not want either to inject some refrigerant in as I don't have a recovery tank to purge the sytem afterwards.
Fianally, I thought I could use an ultrasonic detector (which I do not have yet) instead, but I imagine I would also need a compressor (or is a pump just as good?)? Unless the system will anyway build up pressure (when the car + AC are running) even when no refrigerant is present within the system???