AC Compressor Going Bad?

[Jeff 96 Camry]

96, 2.4L, 275,000 miles. Original owner. During the 3 year-36,000 warranty it was at dealer 2 times because it lost the charge and would not cool. After the warranty ran out I have added some freon every few years until now. If I recall I never added oil. The compressor I guess has made a little pitter patter for a while now.

This year we turned the AC on while driving and the belt squealed. So naturally I turned it back off. Later in a parking lot when it squealed I noticed that the engine tried to turn off so I figured it must not be a loose belt. I guess it was pulling it down. It would run OK except for noise only when idling. Now it will not run without squealing and pulling hard on the engine. I checked the belt it is fine. I doubt it is overcharged because it ran last year and seemed a bit low on gas as it did not cool well at end of season.

Does this sound like compressor is going, or gone, bad? Anything else I should do to be sure before ordering $400 compressor?
If I change the compressor should I change other components that might be holding oil or for any other reason?

Thanks for your help

[Jeff 96 Camry]

I tuned AC it on at idle. The compressor is loud now. It was cooling but is loud. I reved up the engine and I heard a different sound and then a bit of a squeal and something changed. The compressor noise went away and the green AC indicator light started blinking and air coming out of vents started getting warm. It's seemed like the clutch might have disengaged...Never seen the light blink before

Thanks

[frenum49]

AC systems require a specific amount of refrigerant to operate correctly. If the system is overcharged and internal pressures rise above safe levels the clutch will disengage and the compressor will not operate. Many people think that they can just add refrigerant to their system and all will be fine. This is not the case. If clutch engagement is a problem on your compressor there are ways to adjust the gap between the clutch and compressor pulley. If your system is overcharged, which I would bet it is, you need to have the system inspected and serviced by a qualified technician with the proper tools at his disposal. This might cost you a little money but it sure is better than buying a compressor that you do not need and then still having to go to a tech to have the system charged correctly.