Calling a/c experts
Thread Starter
Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,171
From: Hermosa
Calling a/c experts
I have a 77 L-48 with original R4 compressor a/c system that has been converted to 134A by Previous owner.
If I needed to add oil to the system via a charge can, which oil would you use?
I don't know what is in there now PAG or Ester. If it is PAG I don't know if it is 46 or 100 or 150 wt oil.
Would something like this oil be appropriate?
http://www.supercool.ac/products/aut...l-charge-3-oz/
Or would I be better off using this?
http://compare.ebay.com/like/4000387...Types&var=sbar
Neither one of these oils state what wt they are. So, is that not important?
If I needed to add oil to the system via a charge can, which oil would you use?
I don't know what is in there now PAG or Ester. If it is PAG I don't know if it is 46 or 100 or 150 wt oil.
Would something like this oil be appropriate?
http://www.supercool.ac/products/aut...l-charge-3-oz/
Or would I be better off using this?
http://compare.ebay.com/like/4000387...Types&var=sbar
Neither one of these oils state what wt they are. So, is that not important?
Thread Starter
Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,171
From: Hermosa
Don't have a leak right now. With a leak freon will be lost and some oil loss is also likely depending on where and how bad the leak is. In that case which oil would be the better option?
Not wanting to discharge, flush and vacuum down and recharge a system just to replace 1 or 2 ounces of proper oil. It seems that one of the two mentioned oils would be an easier and far cheaper option. I'm guessing I'm not the only one who may be wondering.
In my other vehicles where 134a was the original system it's easy to find which PAG oil to use should I need it, but in this case I'm not sure. So I thought someone who knows a lot about a/c might have an idea which way to go.
Not wanting to discharge, flush and vacuum down and recharge a system just to replace 1 or 2 ounces of proper oil. It seems that one of the two mentioned oils would be an easier and far cheaper option. I'm guessing I'm not the only one who may be wondering.
In my other vehicles where 134a was the original system it's easy to find which PAG oil to use should I need it, but in this case I'm not sure. So I thought someone who knows a lot about a/c might have an idea which way to go.
Team Owner
Joined: Jun 2000
Posts: 38,923
Likes: 1,482
From: Southbound
Cruise-In II Veteran
Did the previous owner make the conversion to R134a? If so, can you contact him/her and see what was used?
It is my understanding the older ester oil is not compatible with R134a, hence the use of PAG during conversions.
It is my understanding the older ester oil is not compatible with R134a, hence the use of PAG during conversions.
Thread Starter
Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,171
From: Hermosa
It is my understanding the older ester oil is not compatible with R134a, hence the use of PAG during conversions.
http://www.supercool.ac/products/aut...l-charge-3-oz/
This one claims to be a pag oil compatible with mineral, ester, and pag oils.
http://www.ebay.com/itm/FJC-R134a-Un...rue#vi-content
Neither of these products address the viscosity of the oil though. so why not? why is it important in my 134A PAG only systems, but for universal oil not mentioned?
The previous owner did not do the conversion himself, he knows nothing about it.
Racer
Joined: Sep 2009
Posts: 437
Likes: 3
From: Alvin Texas
A little on A/C oil. http://blog.acprocold.com/pagoil.
I used POE in retro fits in the early days when not changing the compressor, it allowed a little mineral oil to mix with the POE. PAG will not mix well with mineral oil, and will rapidly attract water, causing a sludge to form.
I used POE in retro fits in the early days when not changing the compressor, it allowed a little mineral oil to mix with the POE. PAG will not mix well with mineral oil, and will rapidly attract water, causing a sludge to form.
Last edited by bpassmore; Sep 10, 2012 at 08:37 PM.
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Thread Starter
Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,171
From: Hermosa
GM used the heavier viscosity, PAG150
I did find some references today that confirmed that 150 is the correct PAG oil viscosity for the Delphi R4 compressor. If you flush the system and are really sure all mineral oil is gone I guess you could then use the pag oil.I also found today that the ester oils are rated at a viscosity of 100wt.
If I had to guess I would probably bet that the conversion was done with ester oil and the hoses were not replaced. (they look old) and that would mean that a 100wt oil is in the system.
I does work well in any case.
Thread Starter
Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,171
From: Hermosa
I used POE in retro fits in the early days when not changing the compressor, it allowed a little mineral oil to mix with the POE.