AC compressor Oil
Thread Starter
Burning Brakes
Joined: May 2014
Posts: 884
Likes: 128
From: Rhine Georgia
AC compressor Oil
Please read carefully.
I converted to R134a couple of years ago. I'm installing another R4 compressor. I was running Ester oil with R134a for 2 years in the first compressor. The new R4 came filled with PAG oil. Can I switch to PAG oil since I've been running R134A for 2 years or do I need to drain the new compressor and fill it with Ester Oil?
I converted to R134a couple of years ago. I'm installing another R4 compressor. I was running Ester oil with R134a for 2 years in the first compressor. The new R4 came filled with PAG oil. Can I switch to PAG oil since I've been running R134A for 2 years or do I need to drain the new compressor and fill it with Ester Oil?
Burning Brakes
Joined: Mar 2006
Posts: 829
Likes: 131
From: Spartanburg SC
Please read carefully.
I converted to R134a couple of years ago. I'm installing another R4 compressor. I was running Ester oil with R134a for 2 years in the first compressor. The new R4 came filled with PAG oil. Can I switch to PAG oil since I've been running R134A for 2 years or do I need to drain the new compressor and fill it with Ester Oil?
I converted to R134a couple of years ago. I'm installing another R4 compressor. I was running Ester oil with R134a for 2 years in the first compressor. The new R4 came filled with PAG oil. Can I switch to PAG oil since I've been running R134A for 2 years or do I need to drain the new compressor and fill it with Ester Oil?
Drifting
Joined: Aug 2005
Posts: 1,443
Likes: 65
From: Wauconda IL
I’m surprised it ran for 2 years with the wrong oil.
R-134a requires the use of PAG oil.
You will need to flush your entire system to get rid of any remaining Ester oil- Including your new compressor if it’s not specifically labeled as R-134a or PAG filled before you introduce PAG oil into the system.
Elm
R-134a requires the use of PAG oil.
You will need to flush your entire system to get rid of any remaining Ester oil- Including your new compressor if it’s not specifically labeled as R-134a or PAG filled before you introduce PAG oil into the system.
Elm
Last edited by ezobens; Sep 28, 2018 at 10:21 PM.
Le Mans Master
Joined: Apr 2011
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From: Hermosa
Had a 1976 L-82, 4-sp
Joined: Mar 2011
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From: Some days your the dog and some days your the hydrant.
Royal Canadian Navy
Did the ester oil cause the failure of the old compressor? If the new compressor came with pag oil specified by the mfg'r, why would you change it to ester oil?
Thread Starter
Burning Brakes
Joined: May 2014
Posts: 884
Likes: 128
From: Rhine Georgia
why would you change it to ester oil?
Did the ester oil cause the failure of the old compressor?
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Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,171
From: Hermosa
OP if you still have the original and it's just the seal leaking then replace the seal, don't buy a new compressor. I have replaced the seal on mine twice so far. The new double lip seals don't last. The original ceramic style seals are better.
If the compressor failed ie seized then you may need to flush the system of debris from the old compressor. What you do depends on what failure you had.
Ester is used for conversions to eliminate the flushing of the system and replacement of the hoses as would be required if you ran 134a with PAG. As I said PAG and mineral oil are not compatible so any residual mineral oil will contaminate your PAG if the system is not flushed.
Ester is compatible with both PAG and mineral so flushing is not required for it's use in either a PAG or mineral oil system.
Last edited by REELAV8R; Sep 29, 2018 at 04:23 PM.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
With the mix of oils you now have in your system, it would be best to flush the system before installing the new compressor and only filling with PAG oil.Yes, PAG oil will mix with ester oil. But you may still have some left over mineral oil in there (which is why ester oil was used). No sense risking a new compressor when you have the system open and can flush it pretty easily for $30. Most auto parts stores sell A/C system flush kits. You just need to blow all the residual stuff out that you can, then install the compressor and PAG oil; vacuum it down for 30 minutes or so and charge it with refrigerant.
Another reason to flush is that you don't have any idea how much oil is in the system now. Flush it clean and then add the correct amount of oil.