Long story short - I have had a veeery slow leak in my AC (in the evaporator core) for years. My tactic has simply been to recharge the AC every year or so once it gets hot. Well, that finally came back to bite me in the butt. I overcharged my AC like nothing else. I began by putting one can in, and became concerned that it was already overcharged, so I released some pressure. Well, the AC started blowing hot again. Now, you might ask - "Why didn't you read the gauge, you idiot?". I did, but the needle jumps around, and it was going all the way into the red when the compressor was cycling (or when the engine was on, not sure which). It also doesn't help that the gauge is extremely poorly designed, but I blame myself. So that's why I released some. Then I notice the AC blowing hot. Lamenting my loss of 13 dollars, I sheepishly go back into the store, and buy another can...and charge the AC with it. The pressure builds and builds and then, on the passenger side of the car, right near the front, I hear a "POP", and see a small cloud of what I assume is refrigerant. This happened several more times. I cursed myself into several different unpleasant afterlives (Hel, Tartarus, and Naraka, among others). The AC ran hot, then cold. The next day, the AC ran so cold I thought I might develop hypothermia. And the day after, the AC only blows hot. So my question is this - what did I break? I have no ODB-II codes (aside from a nagging P0420), and I cannot tell if the compressor is cycling. I will probably have to replace whatever I broke myself, so I have my service manual and tools at the ready. This is what happens when you put aside the repairs you need, so don't do that, or you get to sit all day in the hot sun and fix your beloved Prius in a parking space. Then, the sun goes down and you get to be eaten by mosquitoes while you do it. So...don't put those repairs off.
It sounds like the initial discharges came from the ac compressor built in over pressure vent release. I would put some dye in, fix the source of the leak and then have the professionals vacuum the system and recharge.
One of my issues is that nobody around here will work on a hybrid, even just to evac and charge the AC. I have informed them many times over how dumb that is, and still, they refuse to do it. They say they're afraid of the high voltage. They don't listen when I inform them that recharging the AC has nothing to do with the HV system. The dealership around here isn't much better. I may need to do this myself.
