auto AC question

Hopefully you filled suction port of compressor with PAG oil. Instructions with new compressor should have told you how much to put. That will put oil in compressor when engaged the first time. If not, disconnect lines again and add oil to port. probably 4 ounces. There is still oil in system unless flushed and a little extra won't hurt. You should evacuate but no longer than system was open it will be fine. All info says evacuate so moisture will be boiled out but I have done many of my fleet vehicles when I just didn't have time to evacuate with absolutely no issues. You may have to bypass low pressure switch to get compressor to come on to help freon go in otherwise it takes forever.

This aint someones elses fleet vehicle, you just ponied up for a brand new compressor you need to get the air out of that thing. Air is not a refrigerant, harbor freight sells cheap vacuum pumps these days an air operated model as cheap as 15 bucks. Dont know if they work or not but for one shot perhaps. My local mechanic can usually be talked into a vacuum and charge for about 100.. which isnt bad considering the cost of refrigerant.

We could argue the proceedures for days, but I get enough of that at work where it is either me or guys that work for me that wrote them.   For three of the major compressor manufacturers anyway, give me another 20 years I might get to them all.

The moisture is bad, but that is gross bad as in it will break quickly from acid or icing. The air is bad as well because oxygen is an oxidizer and causes corrosion in the long term. Even the nitrogen plays its part in early failure as it raises the discharge and lowers the suction pressures which stress every component of the system.. not beyond immediate failure or the safeties but old hoses have thier limits.

I am seeing prices of $15 dollars for 12 ounces of 134a from the autoparts stores these days.. that is getting me to shy away from some of my old practices of just dumping in some charge and hoping for it to last awhile.

If you are replacing the compressor it is recommended to replace the Dryer/Accumulator and if the system has an Orifice tube you have to relace too. A burned compressor more than likely would contaminate the oil, therefore to do it right, you need to flush the system. I learned how to fix the Auto AC 5 years ago, so I am no claiming to be an expert. So far I have done 6, 2 of them R12 retrofit. I have read a number of literature to understand what needs to be done. Yes, you need to evacuate the system for at least 20min, I do more. Autozone would loan you one. The moisture needs to be remove from the system in order for the R134a to work properly. Now if you where using R12a (EnviroSafe) you don't need to be concern that much about moisture, yest you need to do vaccum. Envirosafe has been an awesome finding for me. Cheaper, works at lower Hi pressure, uses less, and makes retrofit any R12 system a joke. No need to change o-rings or oil. Check out http://www.es-refrigerants.com/ if anybody is interested. I have two R12 retrofit and they blow really cold air and is a lot better retrofit than R134. I said that because R134 Hi pressure is higher, putting more stress on the compressor. Also, is totally safe. Did you know that R134 can cause testicular cancer? I bet that is if you are expose to it a lot. Anyways, just wanted to share that.



P.S. I am not associated with this company. I just excited about a great product.

1 can of R12a is $4.50.

I have my daughter 88 Volvo's running on this. So far, so good.

To what micron should an auto a/c be pulled down to? i noticed a time of 20 min. or so was given but i would say a micron gauge and a little effort could save a few dollars in the long run. Also i would weigh in the charge if it was me. But on the other hand i have seen quick jobs,no vacuum couple of cans from discount auto and away we go. still working sooo...........

Is there such a thing as just a 'charge' on the system? DIY? My air works but is not as cold as it used to be.

Thanks and apologies for the thread jack.

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i see it finally hit 70 in minisoda

Thanks Dave!