: Where do I install PAG oil for new AC compressor?



Keymaster
08-05-13, 02:13 AM
Hello,

I have looked far and wide but I can't get a conclusive answer to my question. I have a 2002 Escalade. I need to replace the AC compressor. Anyone who has owned this vehicle long enough will go through this process. There is a service bulletin on this matter and it has been well documented. I also plan on replacing the dryer and the orifice tube as well.

My main question is, where do you install the PAG oil? Let me start with what I DO know:

I have documentation on how much PAG oil this vehicle takes (11 ounces)
I know that you are supposed to empty oil from new compressor and re-add the remaining oil plus what you drained out. My new compressor is dry, so there is none to drain.
I am reading that you also install some of the oil into the dryer. There is a Youtube video that documents this as well.

What I cannot find is, what port on the compressor does the oil go? Small hole, which I believe is the high side, or the larger hole, which I believe is the low side?
Also, which hole on the dryer does the oil go?
Lastly, how much oil goes into each?

I tried locating a Chilton manual at a couple of auto parts stores recently, but have not been able to find one for my vehicle. Usually these manuals are good for these types of tidbits.

I have all the other items in place and ready to go: gauges, adapters to fit gauges to R134 lines, vacuum pump.

Thanks in advance for any help that can be provided for this issue.

the cadillac man
08-05-13, 03:29 AM
Hello,

I have looked far and wide but I can't get a conclusive answer to my question. I have a 2002 Escalade. I need to replace the AC compressor. Anyone who has owned this vehicle long enough will go through this process. There is a service bulletin on this matter and it has been well documented. I also plan on replacing the dryer and the orifice tube as well.

My main question is, where do you install the PAG oil? Let me start with what I DO know:

I have documentation on how much PAG oil this vehicle takes (11 ounces)
I know that you are supposed to empty oil from new compressor and re-add the remaining oil plus what you drained out. My new compressor is dry, so there is none to drain.
I am reading that you also install some of the oil into the dryer. There is a Youtube video that documents this as well.

What I cannot find is, what port on the compressor does the oil go? Small hole, which I believe is the high side, or the larger hole, which I believe is the low side?
Also, which hole on the dryer does the oil go?
Lastly, how much oil goes into each?

I tried locating a Chilton manual at a couple of auto parts stores recently, but have not been able to find one for my vehicle. Usually these manuals are good for these types of tidbits.

I have all the other items in place and ready to go: gauges, adapters to fit gauges to R134 lines, vacuum pump.

Thanks in advance for any help that can be provided for this issue.

Everything goes in on the low side not the high side(that side is dangerous if careless)
One can should do but I would consult with a dealers service manager before I continue

I have a service manual and I will look and see if it has the oil amount listed

TLMC
08-05-13, 09:58 PM
Drain the oil out of your old compressor and measure, that is the amount you put in the new compressor. you can put in either hole before you attach the lines it will be about 3 or 4 ounces of oil.Add about 2 ounces of oil to the dryer and you are good to go. 11 ounces is for a complete new system, you are not replacing the 2 evaporators or the condenser which all contain oil. When an a/c system is charged by an a/c machine with oil it is charged on the high side. I know I am a mechanic and have been for over 35 years.

Keymaster
08-05-13, 11:54 PM
Drain the oil out of your old compressor and measure, that is the amount you put in the new compressor. you can put in either hole before you attach the lines it will be about 3 or 4 ounces of oil.Add about 2 ounces of oil to the dryer and you are good to go. 11 ounces is for a complete new system, you are not replacing the 2 evaporators or the condenser which all contain oil. When an a/c system is charged by an a/c machine with oil it is charged on the high side. I know I am a mechanic and have been for over 35 years.

Thanks for the reply. I found a couple of articles last night that referred to other GM vehicles that were basically identical to the Escalade (either Yukon, Denali, etc.) The literature posted said that out of the 11 ounces in the system, 3 of those were in the rear portion of the system. It said to pour 1 oz in the dryer. There is apparently an ounce that goes in the condensor, although I'm not fooling with that. That leaves 6 ounces to go into the compressor. Another article I read said to use 5 ounces in the compressor. That would give me the 11 ounces of total oil.

My dad and I had a healthy discussion about this topic this afternoon. He works on home AC systems where the compressors come pre-filled with oil from the factory. One thing that want to understand about the ac system in my Escalade is, once the oil is poured into the different locations (dryer, compressor), does it stay there? In other words, the only thing I thought that actually circulated throughout the system is the freon. Does the 5 ounces of PAG oil stay in the compressor, or does a portion of it circulate through the lines along with the freon? And why do you need oil in the dryer?

Thanks again for your input.

Keymaster
08-12-13, 09:20 PM
Just a followup question. Has anyone injected the PAG oil through the low side before installing the freon? I talked to a gentleman about my situation and he recommended evacuating the system, replacing the orifice tube, putting a vacuum on the system, injecting the PAG oil into the low side and THEN adding the r134a to the low side. I was gonna take the low side hose off the compressor, use a piece of clean hose along with a funnel and pour the PAG oil directly into the compressor. Button everything up, remove the belt, turn the pulley 10-15 rotations, re-install the belt and they add the r134a.

I'm really looking for someone who has tried this or knows from experience whether or not that much oil can be added through the low side. From what I've read, it wouldn't matter, as the oil is circulating throughout the system anyway. I would be adding about 7 oz total.

Thank you.

the cadillac man
08-12-13, 09:39 PM
Just a followup question. Has anyone injected the PAG oil through the low side before installing the freon? I talked to a gentleman about my situation and he recommended evacuating the system, replacing the orifice tube, putting a vacuum on the system, injecting the PAG oil into the low side and THEN adding the r134a to the low side. I was gonna take the low side hose off the compressor, use a piece of clean hose along with a funnel and pour the PAG oil directly into the compressor. Button everything up, remove the belt, turn the pulley 10-15 rotations, re-install the belt and they add the r134a.

I'm really looking for someone who has tried this or knows from experience whether or not that much oil can be added through the low side. From what I've read, it wouldn't matter, as the oil is circulating throughout the system anyway. I would be adding about 7 oz total.

Thank you.

I would inject it after you put everything together and have replaced all the parts

Ollie8974
08-23-13, 03:13 PM
A new compressor will usually have the correct amount of oil installed.
Ask when you purchase the compressor.