How many PAG oil needs to be added to new compressor?

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Tony_1992

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Hey guys, I'm recently replacing the compressor and the drier, or the receiver. The seller said that the compressor comes with pre filled PAG, but needs to be poured out and add some new PAG oil into it. But in that case, how much PAG oil should I add into it?
Also,when replacing the drier, how much PAG oil needs to be added?

Thank you!
 
This is a difficult question, because it is hard to tell how much oil is left in the rest of the system, more so if there was a leak before replacement. Most of the oil should have been in the old compressor and old dryer. Total system oil charge is 7 oz. Since you are replacing the compressor and the dryer, I'd put 6 oz in the compressor. Be sure to rotate the inner part of the clutch by hand several times as you are draining the shipment oil. Also, after installing the compressor, but before charging, be sure to again rotate the inner part of the clutch by hand several times to make sure all the moving parts of the compressor have oil before starting the engine.
 
joegr said:
This is a difficult question, because it is hard to tell how much oil is left in the rest of the system, more so if there was a leak before replacement. Most of the oil should have been in the old compressor and old dryer. Total system oil charge is 7 oz. Since you are replacing the compressor and the dryer, I'd put 6 oz in the compressor. Be sure to rotate the inner part of the clutch by hand several times as you are draining the shipment oil. Also, after installing the compressor, but before charging, be sure to again rotate the inner part of the clutch by hand several times to make sure all the moving parts of the compressor have oil before starting the engine.
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Thank you
I'm thinking of drill a hole in the old drier and measure the volume of oil in it, and add the same amount of new PAG oil into the new drier. Then, I'll drain the new compressor and add 6oz minus oil added to drier, to the new compressor. Thank you!
 
No need to add any to the dryer. It's not needed there, but it ends up there anyway. It's only needed in the compressor.
The idea is to measure what was in the old compressor and the old dryer. Then add those two amounts together and pour that total amount in new oil into the new compressor. (Note that this is a scroll, so you don't have to worry about pumping liquid (too much oil in the compressor to start with).

The problem is that if you had any failure that resulted in a leak of refrigerant and/or oil, then the amount of oil remaining in the old components will not be correct.
 
Joe, what (negative) happens if the incorrect (not enough?) amount of PAG oil is put in a new A/C compressor when being installed?

joegr said:
No need to add any to the dryer. It's not needed there, but it ends up there anyway. It's only needed in the compressor.
The idea is to measure what was in the old compressor and the old dryer. Then add those two amounts together and pour that total amount in new oil into the new compressor. (Note that this is a scroll, so you don't have to worry about pumping liquid (too much oil in the compressor to start with).

The problem is that if you had any failure that resulted in a leak of refrigerant and/or oil, then the amount of oil remaining in the old components will not be correct.
Click to expand...
 
Much too little oil, and the compressor fails and contaminates the entire system. (You can be a little low on oil and be just fine, as long as none ever leaks out.)
Too much oil, and cooling capacity is reduced.

It's best to have just the right amount, but a little extra is better than not enough.
 
Soooo sad. I find a mechanist to replace the compressor. After that we added 2 cans of R134a but there's still no cooling at all!!!

Is that the oil problem? I drain the old oil and add about 6.5 oz.

My world almost collapsed.
 
No, not related to oil.
Is the compressor clutch engaged?
What is the low side pressure?
What is the high side pressure?

For how long was a vacuum pulled on the system? Was a micron gauge used? If not, what kind of vacuum pump (how low of a vacuum could it pump)?

Compressor OEM or aftermarket?
What was the reason for replacing the compressor?
 
just for shiggles, is the air coming out of the vents just not being cooled, or is it heated?
 
joegr said:
No, not related to oil.
Is the compressor clutch engaged?
What is the low side pressure?
What is the high side pressure?

For how long was a vacuum pulled on the system? Was a micron gauge used? If not, what kind of vacuum pump (how low of a vacuum could it pump)?

Compressor OEM or aftermarket?
What was the reason for replacing the compressor?
Click to expand...
The clutch starts turning when I open the A/C.

High/low pressure cannot be tested, cause I don't have enough R134a now.

It was an aftermarket compressor. But that shouldn't be the problem, cause someone replaced it several days ago and it did work.

I think the system has being pumped by 20 minutes? The reason to replace the compressor is because guys in FireStone did a test and they said the low pressure is high but the high pressure is low, which means a failed compressor.

Pumps rent from AutoZone like this:
Amazon.com: Zeny 3,5CFM Single-Stage 5 Pa Rotary Vane Economy Vacuum Pump 3 CFM 1/4HP Air Conditioner Refrigerant HVAC Air tool R410a 1/4" Flare Inlet Port, Blue: Industrial & Scientific
 
1LoudLS said:
just for shiggles, is the air coming out of the vents just not being cooled, or is it heated?
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Thank you for your help. When I drive, the air comes out is just about the same with the ambient temperature. So I think the DCCV is working normally. And when I turned it to full heat and then turn it to cooling(at least looks like cooling), the air did becomes very hot and then cool down to ambient temperature.
 
no matter how much refrigerant is in the system, gauges can be hooked up and readings can be read. those readings are what you use to figure out whats wrong. (and if you know you don't have enough refrigerant in your system, I'm not sure how you can be surprised that the system is not working)

so you can either get the correct readings and go from there, or we can just keep throwing out wild guesses and probably never figure it out.
 
1LoudLS said:
no matter how much refrigerant is in the system, gauges can be hooked up and readings can be read. those readings are what you use to figure out whats wrong. (and if you know you don't have enough refrigerant in your system, I'm not sure how you can be surprised that the system is not working)

so you can either get the correct readings and go from there, or we can just keep throwing out wild guesses and probably never figure it out.
Click to expand...
Yes, you are right. I went to AutoZone this morning to rent a gauge to want read by myself but they said the gauge is out of stock. And they ordered one from another local store and I'll fetch it back tonight. Thank you for your help.
 
Tony_1992 said:
I find a mechanist to replace the compressor. After that we added 2 cans of R134a but there's still no cooling at all!!!
Click to expand...

Tony_1992 said:
It was an aftermarket compressor. But that shouldn't be the problem, cause someone replaced it several days ago and it did work.
Click to expand...

and these two statements to not agree with each other... which is it, did the system work and then stop again? or did the system never work with the new compressor?
 
1LoudLS said:
and these two statements to not agree with each other... which is it, did the system work and then stop again? or did the system never work with the new compressor?
Click to expand...
Oh, I mean some guy in this forum also replaced his compressor, and it worked. I'm using the same type of compressor with his.
 
1LoudLS said:
and these two statements to not agree with each other... which is it, did the system work and then stop again? or did the system never work with the new compressor?
Click to expand...
IT EVENTUALLY WORKS!
I don't know why. But today I used a pump to check that the whole system is sealed, and then evacuated the whole system for 45 minutes. Then I gradually added 2.5 cans R134a refrigerant and miracle happened! Cooling air comes from the vent which is awesome!
Thank you for your following and help!
 
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