Why did my new AC system stop?
#1
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On my 99 Camaro V8 I changed the compressor because it was making growling noises and it was leaking. I also changed the orifice and the dryer. I charged the dryer prior to installation with 3 1/2 oz of PAG oil. The old orifice had one or two pieces of metal shavings but other than that the screen was very clean. Did not flush the system. After I changed all this it was cooling very weak the first day and the next day it just stopped cooling. The pressure was not equalizing from both sides of the orifice when the engine was shut down. So I opened it up again. I found that the new orifice was completely blocked. A lot of black oily grain-like crud in the new orifice. The new compressor is from 4Seasons and it was supposed to be pre charged with PAG oil. I don't think it was. Now what should I do? Flush the system and how? Did I get a bad compressor? I believe you can only flush the evaporators, condensers and lines. Do I need to flush each component separately? Change the condenser and compressor? Thank you guys in advance for any help I could get.
#2
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Grain-like... Could be the desiccant from the dryer? Did you pull a vacuum on the system before charging it with 134a? Flush the evaporator separately from hoses/lines, replace the condenser and dryer
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swathdiver (09-08-2022)
#3
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If it was mine I’d flush everything but I’m a mechanical contractor so I have access to everything needed.
You’re gonna need to flush with rx11 and nitrogen, might be cheaper to and definitely better to replace everything. At the minimum a new drier and compressor oil drain and replace with factory recommended amount. The metering device filter is going to need to be cleaned or replaced. Didn’t see you mention evacuation. I believe in automobiles they call it black death.
The driers desiccant can break down, I’ve only seen that happen in commercial refrigeration system. Desiccant is a grayish to a pale yellow brick color. high acid driers do have a little charcoal speckled in.
I’ve seen black soot from improper brazing people not using a inert gas like nitrogen. Grainy could be metal from the compressor pistons destroying the bores, that would spread throughout the system.
Good luck
You’re gonna need to flush with rx11 and nitrogen, might be cheaper to and definitely better to replace everything. At the minimum a new drier and compressor oil drain and replace with factory recommended amount. The metering device filter is going to need to be cleaned or replaced. Didn’t see you mention evacuation. I believe in automobiles they call it black death.
The driers desiccant can break down, I’ve only seen that happen in commercial refrigeration system. Desiccant is a grayish to a pale yellow brick color. high acid driers do have a little charcoal speckled in.
I’ve seen black soot from improper brazing people not using a inert gas like nitrogen. Grainy could be metal from the compressor pistons destroying the bores, that would spread throughout the system.
Good luck
Last edited by jasons69chevelle; 09-07-2022 at 10:05 PM.
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swathdiver (09-08-2022)
#4
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Thank you jetech, I did pull a vacuum. Was the dryer bad? I reordered a new dryer (GM Genuine), a Condenser and a Compressor and Orifice tube (ACdelco). What I did the first time is that I poured the oil inside the dryer before installation. Did I do it correctly or messed it up? I talked to an AC shop and he said they would never put oil inside a dryer. 4season compressor supposed to be Pre-charged with 3 oz. How should I check to make sure it’s pre-charged. I think the whole AC system requires 9 oz of PAG oil. How do I add pag oil into the system? What side of the dryer do I pour the oil in if I need to do that? A YouTube video says to put oil inside the high pressure side when there is a vacuum on the low side. Do I need to add oil in the evaporator? What do you think about that? I know it's a lot of questions but I don't want to mess it up again. Thank you again for your advice.
#7
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I think your original AC compressor was already shedding metal before you replaced it. A flush of the evaporator, condenser and all lines should help.That initial oil charge should have been spread throughout the system - some each in the drier, the condenser, the evaporator and the compressor. The idea here is to prevent a dry start up of the compressor.
Rick
Rick