AC not working consistently

[ptaylor-01]

Hi, I've been having a problem with my AC on my 96 850 for the past month. Normally, I've just had to put in a can of R134a every other year, and it had been working great.
This summer, it's been blowing cold air for only about 5-10 minutes, and then it will seemingly cut out because it then starts blowing humid warm air. If I turn off the AC button for a couple minutes, then back on, it will usually blow cold air again, sometimes also blowing steam from the vents with a lot of condensation.
On really hot days (over 90) this will work a couple of times, and then it will stop blowing cold air completely. Today, this is how it went on the way home from work for the first 45 minutes on the highway. Then, when driving a few minutes on back roads at much lower speeds after exiting the highway, it suddenly was again able to blow cold air for another 5 minutes.
I did add another can a few days ago, and the pressure is around 40 psi, but there was no improvement afterwards.

Could this be the dryer, or is it more likely to be the compressor or the clutch? I doubt I have a leak, because I do seem to have a good amount of coolant in the system, otherwise it would blow no cold air at all.

[Ozark Lee]

You have the classic symptoms of an excessive clutch gap on the A/C compressor.

https://www.matthewsvolvosite.com/forums ... c&start=20

...Lee

[Krikkit]

I agree Lee.
I had this problem on my 97, the dealer wanted to change the compressor, which would have fixed the problem because a compressor comes with a new clutch.
The difference was I fixed it myself in a few hours with no parts required rather than their $2500 charge.
Many thanks to Matthews Volvo forums for all the great information.
(PS, I printed the article on the clutch gap issue and passed it along to the dealership, don't know if they still change compressors for this problem or not)

[hammertime]

Two out of my three cars have bread bag clips glued into the AC clutch mechanism and they work great.