Zman537

About a year ago I bought an 04 Chevy avalanche. AC compressor went out on it about a week later. I bought an AC compressor from advance Auto I bought peg 46 oil and refrigerant a vacuum pump to put on the lines and a set of gauges. I followed the directions installed a new compressor and the oil and the refrigerant and that compressor lasted 2 days, I was sitting on a hill with the truck at downward angle and heard a loud hissing noise and there was refrigerant and oil leaking out from the rear of the compressor. I took it to compressor back up there to advanced they replaced it but told me that I needed to replace the orifice tube and accumulator as well, but they do not have an accumulator in stock and said it would be one week, so in my hurry I went to oreillys bought a new accumulator got home replaced all the components followedr directions using the gauges and vacuum pump, new oil, new refrigerant. I use the chart to look at my high and low pressure should be, I don't remember what those numbers were is that was 7 months ago but nothing was out of range on it. it lasted me 7 months until today same thing loud hissing noise and refrigerant and oil leaking out the compressor, the compressor still engages. I called advance Auto explain to them the situation but they will not honor the lifetime warranty on this compressor because even though I did buy a new accumulator I did not buy an accumulator from them so I am Sol on this product. So my question is does anybody have any experience with this, do these compressors have a purge valve or blow off valve that I can replace and is it still good or do I have to spend another three and a half hours tearing it off my truck and 350 dollars to buy a new one?

oilcanhenry

Probably needed to flush out your entire A/C system the first time this event occurred to get all the contaminants out of the system. The A/C vacuum pump alone will not do so at all.

At 75°F your low side should be about 35-40 PSI and high side about 150-170 PSI, give or take, for your particular A/C system. Most R-134A air-conditioning systems I have worked on tend towards the higher side of those numbers, which is fine, as that's quite normal, depending on ambient temperatures and so forth. I can always get the
outlet duct temperature down to at least 42°F, and even down to 38°F, depending on many factors besides the outside ambient temperatures, on a _solid_ A/C system.

The old R-12 Freon units would run lower pressures then the newer R-134A systems, or a conversion from the old R-12 to R-134A refrigerant, which absolutely calls for an entire system flush, if not a new or rebuilt A/C compressor unit as well, at times.

BTW, your Avalanche calls for 43.00 oz.of R-134A if it has back-side A/C, 25.5 oz. without. PAG 46 is 11 oz. with back-side A/C and 8 oz. without back side A/C. On a completely flushed-out system, a couple of ounces of extra PAG wont hurt at all, in my experiences. Might want to add some green leak detector to your ride anyhow.

tech2

the dealer has a kit of metal screens that are made to fit in to the compressor at the suction line. this protects the compressor from metal floaters. its pretty hard to find though....most dealer staff aren't aware of it and I can't remember the part number.