I am needing to evac my a/c system on my 2001 ss monte. Currently there is not enough refrigerant pressure to kick on the compressor. I am looking to learn how to clear out the system. I also am unsure if (how do you know if it needs oil) or how the compressor oil is filled.
Any information on how to do this would be much appreciated.🙂

 

I hate to say it, but this isn't a DIY friendly job. A good system vacuum is likely going to cost more than you're going to want to spend for a one time job.

If the pressure is low, the system is leaking. Probably best to top it off and add some UV dye to locate the leak first.

Once that's found And you know what you've got to replace, you can have them reclaim the old refrigerant, bring it home to replace the parts you need to (and any you want to as preventative maintenance), then take it back to have a vacuum pulled on it and a fresh charge + fresh oil put in.

Alternatively you could drop it off at a shop and let them do the whole thing if you don't mind spending the added money and want to lower your risk of missing something.

 

Ok I had my a/c evac down to 560 microns and recharged. It seems to be working BUT when it’s idling the compressor is NOT kicking off and on. Not sure if it’s normal at idle to stay engaged or if there’s anything else I need to look into or repair. Am I right in assuming that the compressor should be cycling even at idle?!

 

It should occasionally cycle on and off, but it shouldn't be a frequent thing (it can stay on for quite awhile in a single shot - think how long your house AC runs in the middle of summer, especially if its been turned off for awhile and its trying to get back to temp).

The hard part is that compressor duty cycle depends on several variables. The most important thing is - are the temperature drops in the car and the hi/low pressures ok?

If its running constantly and temperature drops are mediocre, then there's definitely an issue to look deeper into.

 

I am going to hook gauges back up later today and see where the pressures are on H/L. It has a full Freon charge. It was evacuated down to 560 microns then filled. I could be over thinking this. But I am also going to drive it around and see if it stays cold or if it freezes up and goes hot air.
I will put up the readings today to help diagnose.

 

I think taking some readings and going for a drive to give it some time to work is the best bet. Id drop a thermometer on the passenger floor well and stick another in a vent so you have some data for temp drops, just make sure to set it to recirc.

If its cooling fine and you come back and verify the pressures are OK later, then I wouldnt worry about it (assuming the on/off system for the compressor worked fine before of course; different story if it had some kind of known electrical issues prior).