New ac compressor

08ellimted

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Hey y’all. 2008 Ford Expedition el limited with the rear air conditioning
My og ac compressor locked up at 183,*** miles I flushed the system out prior to installing the new one. I added the correct amount of oil (7oz of pag 46) and pulled a vacuum and let it hold for an hour it didn’t go up at all in the vacuum being held (I’m pretty knowledgeable on ac systems so I did this at home) I’ve added (3 18 oz cans) 54 oz of Freon with the gauges being used (rented from Autozone) and I still have no ac the clutch engages and works like it should and the low side hose gets cold running does anyone know what could be the cause of it? Could the compressor be bad even though it’s a brand new one? I’m lost and about to take it to a shop and let them see what’s going on with it. There is no leaks anywhere and everything is tight it was blowing cold for 10 minutes for the drive from my home to Autozone to return the vacuum pump and gauges I rented then it stopped working. I bought another can of r-134a while I was there and the gauge on it reads zero I was thinking the gauge is bad so it was swapped out with another and it still read zero on the low side anyone know what could be the problem?
 

max78

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Either Look under the hood, or call the dealer to find out how much refrigerant it should take. 54oz sounds like too much, my 09 with rear air only calls for around 32oz from what I remember. If it's overcharged it wont work worth a dang. Fix that if its too full and test

What are your pressures at 2k rpm?

If your pressures are good and your system is cycling the compressor constantly, or occasionally? look at replacing both thermal expansion valves. Debris can very easily get stuck in the small hole and throw everything off. I replaced mine at 200k because of poor performance and it made a world of difference.
 
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twodollars

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If your reading zero on the low side and it worked for a few minutes, I would imagine you lost the whole charge. I'd look for a oily leak on all the lines a d condensor. Any uv dye added? Be easy to find if it's not in one of the evaporator
 
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Usually with a failed compressor nowadays, the condenser needs to be replaced as well due to little bits that don't get flushed out. You didn't mention the high side pressure; it's probably worth a look. If the discharge pressure is high and the low side is near zero, the expansion valve is likely plugged by debris.
 
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