Most every vehicle I’ve owned in recent memory (of those that -had- A/C ) had a little window to view the level of freon or refrigerant. Question is though… um, what am I looking for ? What are the sign or signs that something is wrong? Is the little window only there for a real mechanic to see if, in test conditions, if the coolant dye is moving? Am I supposed to see cloudy stuff in the little eye, or empty blackness, or swirling streams of stuff or what?
Specific to most recent case:
I have a '99 Ford F150, and I suspect that the A/C just isn’t up to snuff (and being a '99, it is out of warranty) is there something that I can look at to confirm suspicions?
Further, is adding refrigerant all that hard, as long as I get the right kind?