Replacing A/C Compressor

Tiny
TXCHEVY
  • MEMBER
  • 2005 CHEVROLET TAHOE
  • 4.8L
  • V8
  • 4WD
  • AUTOMATIC
  • 100,000 MILES
Hello, I just finished reading the instructions on recharging a a/c unit, and it is very informative. I am about to replace the a/c compressor, condenser, accumulator dryer, orifice tube, and put new O-rings in as well. I also purchased 8 oz. Of PAG 46 oil, and this is where I think I am overthinking this procedure. I understand that each component requires so many mL of PAG oil, but what I don't know is how to know how much to put in. When the refrigerant is recovered, I'll swap the new parts in, (do I need to flush still even though I'm replacing everything but the evaporator core?), Vacuum the system/vacuum test, and then recharge the system. But when does the oil go in, and how much do I use since I am replacing all those components? Any guidance is greatly appreciated, because I am going insane scouring the internet for answers.
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Saturday, April 9th, 2016 AT 2:50 AM

8 Replies

Tiny
WRENCHTECH
  • EXPERT
You will add oil to most of the components as you assemble the system. To tell you the truth, most of it is guesswork from past experience. The first thing you have to determine is if the new compressor comes with any oil already, most do. Use new only on compressors. Never use a Reman. I would start with 2.0 oz. in the system Once the system is assembled, rotate the compressor about 20 revolutions to purge the liquid from it before the system is run. If this system has a rear unit.

Here are tow guides that can help

https://www.2carpros.com/articles/replace-air-conditioner-compressor

and

https://www.2carpros.com/articles/re-charge-an-air-conditioner-system

Check out the diagrams (Below). Please let us know if you need anything else to get the problem fixed.

Cheers
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Saturday, April 9th, 2016 AT 4:28 AM
Tiny
TXCHEVY
  • MEMBER
Thank you for answering my questions. Where exactly do I introduce the oil into the condenser and accumulator? Also, since I'm replacing all these components is a system flush necessary? The reason why I'm doing this is because my compressor stopped working. The clutch wasn't engaging rather. I figured it would be the perfect time to replace the other parts besides the evaporator core.
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Saturday, April 9th, 2016 AT 5:14 AM
Tiny
WRENCHTECH
  • EXPERT
You simply pour the oil into the component before installing it. Be sure to coat all the O-rings with refrigerant oil before installing them.
I wouldn't be too concerning with flushing. It doesn't sound like it had a catastrophic failure to start with.

You know, there are a whole lot of reasons for a clutch not to engage that aren't the compressors fault. I assume you did proper diagnosis before condemning that compressor are the issue.
If in fact the compressor did seize of fail internally, you need to find the reason for the original failure. Check the cooling fan operation very carefully. This has a 2 speed fan system and you need to make sure both speeds are working.
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Saturday, April 9th, 2016 AT 5:26 AM
Tiny
TXCHEVY
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How do I make sure both speeds are working? I've been learning as I go. I'm 31 years old and just recently found the desire to work on our vehicles. Anyway, I guess some history of this issue would be helpful. One day my wife said the A/C stopped blowing cold air. It still blows air, just not cold. I got one of the cans of R134A with the gauge, and when I hooked it up the gauge immediately went into the red. I think that means overcharged? Forgive my ignorance. I then realized the clutch wasn't engaging. I checked the relay, swapped it out and no change. I guess after some brief online research (this happened last summer) I decided to purchase a new compressor. I never got around to it, and tried to convince my wife that we should just trade it in. Because I was being a lazy ass. Well fast forward to now and it's getting warmer again here in San Antonio. I finally became motivated to take care of this. So I purchased a new condenser, accumulator dryer, orifice tube, and new O-rings. I read it's the smart thing to do to replace all of these things when replacing the A/C compressor. I guess I figured doing all of that would fix this issue and make my wife happy. Please tell me I may not have needed to buy all that stuff! Though. The tahoe is 11 years old. Probably still a good idea. Whatcha got for me?
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Saturday, April 9th, 2016 AT 5:39 AM
Tiny
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  • EXPERT
Here is a guide that can help you see whats going on

https://www.2carpros.com/articles/car-air-conditioner-not-working-or-is-weak

Please let us know what you find.

Cheers
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Saturday, April 9th, 2016 AT 6:28 AM
Tiny
TXCHEVY
  • MEMBER
Thank you. You've definitely been extremely helpful. Thank you.
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Saturday, April 9th, 2016 AT 6:57 AM
Tiny
ROB456
  • MEMBER
I probably did not have to replace my compressor, dryer, and condenser, but I did. I followed the PAG suggestion above but added one more ounce to tubes especially the incoming to the compressor. To recharge the Freon I jumper-ed the low-pressure switch to cut on the compressor and filled until I hit the green on the gauge. Tada new fully working cold blowing system. $175.00 total cost. Anyways this job surely can be done by an amateur.
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Monday, April 30th, 2018 AT 11:49 AM
Tiny
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Sure it can, that's why we are here to help the average person get the job done.
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Monday, April 30th, 2018 AT 1:52 PM

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