PAG 46 oil after ac repair

[Shoelessjoe]

Hey guys,

Long story short, the ac has been out on our 2004 lx for two summer now and its time to solve the issue. I ordered a couple of new rear lines and have all the equipment to run a vacuum but was wondering if I need to add some PAG 46 oil because it has sat for so long. The compress and all the major components are original as I am just replacing two rear lines.

Any information would be greatly appreciated.

Thanks, Joe

 

[Mark WV]

just my humble opinion, but I have replaced many lines, condensers, etc and have never added any additional oil with no ill effects. Only time I add oil is when replacing the compressor.

My limited understanding is that most of the oil in the system will settle to the lowest point in the system which is usually the compressor.

 

[flintknapper]

just my humble opinion, but I have replaced many lines, condensers, etc and have never added any additional oil with no ill effects. Only time I add oil is when replacing the compressor.

My limited understanding is that most of the oil in the system will settle to the lowest point in the system which is usually the compressor.

Compressor will use/retain about 40-50% of the PAG oil. The rest will reside in the Drier, Condenser, Evaporator or be transported in the refrigerant itself through the system.

IF the system is completely evacuated...it should be assumed that a certain amount of oil has been lost (as it is miscible in the refrigerant). IF the OP's system has been open to atmosphere for 2 years....I would not even consider just replacing the lines and buttoning it back up. I would flush all the lines, replace the drier, pull a DEEP/LONG vacuum on it and add oil along with the recharge.

The result of having too little oil (a small amount) is simply shorter compressor life. The result of having too much (a few ounces) is reduced cooling capacity.

 

[Shoelessjoe]

Compressor will use/retain about 40-50% of the PAG oil. The rest will reside in the Drier, Condenser, Evaporator or be transported in the refrigerant itself through the system.

IF the system is completely evacuated...it should be assumed that a certain amount of oil has been lost (as it is miscible in the refrigerant). IF the OP's system has been open to atmosphere for 2 years....I would not even consider just replacing the lines and buttoning it back up. I would flush all the lines, replace the drier, pull a DEEP/LONG vacuum on it and add oil along with the recharge.

The result of having too little oil (a small amount) is simply shorter compressor life. The result of having too much (a few ounces) is reduced cooling capacity.

How would one go about flushing the lines?

Thanks,

 

[vipergrhd]

If the system has been empty for that long replace your receiver/drier and add some oil in your system before you charged about 2 oz. is a safe amount. Flushing is no longer necessary unless you grenaded a compressor and all you can flush really is your lines the newer
condenser and evaporator is next to impossible to clean due to smaller cores. PAG 46 is ND-8 oil is that what's on your underhood label?

 

[Shoelessjoe]

If the system has been empty for that long replace your receiver/drier and add some oil in your system before you charged about 2 oz. is a safe amount. Flushing is no longer necessary unless you grenaded a compressor and all you can flush really is your lines the newer
condenser and evaporator is next to impossible to clean due to smaller cores. PAG 46 is ND-8 oil is that what's on your underhood label?

This is where I was led to believe its PAG, not 100% sure about the credibility of the website though.

Toyota Refrigerant and oil capacity charts || TechChoice Parts

Oil and refrigerant capacity table for Toyota vehicles

www.techchoiceparts.com

 

[vipergrhd]

Find the underhood label were it states the amount of refrigerant and type of oil required for your vehicle. Most Denso units will use PAG 46.

 

[Shoelessjoe]

Find the underhood label were it states the amount of refrigerant and type of oil required for your vehicle. Most Denso units will use PAG 46.

Thanks buddy, don't know where I'd be without all the smarts on mud!

 

[flintknapper]

How would one go about flushing the lines?

Thanks,

Search 'flushing A/C lines', it should pull several posts with the procedures (I don't feel like re-writing it all here again).

Was the system left open to atmosphere the whole time?

 

[flintknapper]

This is where I was led to believe its PAG, not 100% sure about the credibility of the website though.

Toyota Refrigerant and oil capacity charts || TechChoice Parts

Oil and refrigerant capacity table for Toyota vehicles

www.techchoiceparts.com

PAG46 is correct for your system (PAG oils come in three different viscosity) yours is 46.

 

[flintknapper]

If the system has been empty for that long replace your receiver/drier and add some oil in your system before you charged about 2 oz. is a safe amount.

2 oz. should be enough. It's a guess (at best) as to how the refrigerant was lost (forcefully all at once, or slow leak). Makes a difference how much oil is lost.

Flushing is no longer necessary unless you grenaded a compressor and all you can flush really is your lines the newer
condenser and evaporator is next to impossible to clean due to smaller cores.

Flushing (the lines) is always recommended IF the system has been open for a long period of time, not ONLY when a compressor fails. Newer Condensers and Evaporators are not flushed, not because of their 'size' but because of their construction (parallel instead of serpentine). You can't adequately flush a parallel component. The flushing solution will tend to settle in the bottom and the Air/Other used to blow it out will simply take the path of least resistance.

PAG 46 is ND-8 oil is that what's on your underhood label?

Correct.

^^^^^
Expand for replies.

 

[vipergrhd]

@flintknapper Where were you earlier? Geez.

 

[flintknapper]

@flintknapper Where were you earlier? Geez.

Mowing pasture.

But the OP was always in capable hands and many of our members are willing to help with questions. That's why this is such a great site.