The infamous AC pulley squeak...

[itWRXjustfine]

So my AC pull had started squeaking pretty bad whenever the system cycled, AC on or off, as long as the fan was on. I finally thought to myself, my AC hasn't been on in a looooong time (coming off deployment and returning in winter). So I thought maybe the system needed oil and refrigerant ran through it. BAM cured...ish. Now since then when the AC is off and the system cycles, no noise. When I turn the AC on and it cycles I still get a faint squeak, but not as loud as it used to be. It has 76k on it.

[SD_GR]

If there is no leak, the system will not need oil or refrigerant. If you added these, you either have a leak that you need to fix or you now have a system with the incorrect amount.

How old is the belt? If the belt has 76K consider replacing it, but only with an authentic Subaru belt. Check the roller while the belt is off, maybe it's making noise; if so, replace that too (NAPA would do for that but not for the belt).

Don't run the system with a leak or with incorrect pressures (over-topped).

[itWRXjustfine]

I didn't add any fluid I just hadn't actually ran the AC for a long while. I should pull the belt, but I have been hesitant because I know what a belt squeak sounds like and it doesn't sound like one. I will check anyway though.

[itWRXjustfine]

A little followup: When I had everything apart, taking it back to stock, I did notice a little lack of tension on my belt. Tightened it up and solved everything. I have heard loose belts many many times, and I would have sworn up and down that it was not belt squeal. I guess we all gotta be wrong sometimes...

[SD_GR]

I changed my belts around 80K because of squeaking. Made a huge difference. The belts are coated with something like felt on the inside, they are very quiet when new.