| Refrigerant oil questions [message #287108] |
Fri, 11 September 2015 20:16  |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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I always use the correct oil to match what the vehicle had at manufacture time. The way I understand it there are basically 3 types of oil and several weights at least when PAG is used.
1. Mineral oil was used with R-12 and R-22.
2. PAG was sued in most R-134 applications.
3. Then there was Polyester (POE) oil was used where?
Here is why it is important to me.
When I got my coach about 14 or so years ago the PO had switched it to R-134. I left it that way until a hose rubbed through on the frame, leaked, and needed to be replaced. It is interesting that none of the o-rings were switched to green ones. Everyone I have looked at one it is black but never leaked. At that time seeing no oil leaks on the hose I replaced the hose and dryer and added no oil. I charged it with Duracool and it ran well until now when I developed another leak at the front compressor seal.
Now I am removing the compressor to fix the front seal and I'm sure to loose some oil in the process.
I will recharge it again with Duracool so oil type is not an issue there. What is an issue is what type of oil can I add and not cause a problem with what is already in there.
Can I add POE oil and not cause a problem or do I have to guess that the oil still in it is mineral oil and add some of that?
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: Refrigerant oil questions [message #287113 is a reply to message #287108] |
Fri, 11 September 2015 22:29  |
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Matt Colie
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
Karma: 7
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Senior Member |
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Ken,
As I understand it (lets hope the CRS has hit too hard).
There are three types of oil Mineral, PAG and Ester.
While PAG is available in different weights, that really doesn't matter in your case as it was only used as a OE fill. Hopefully, they had some idea which they wanted. PAG (PolyAlkylene Glycol) is incompatible with everything else. It is very miscible with 134 and less expensive than Ester.
Ester (Polyolester - real close to being Mobil 1) is compatible with mineral oil, but it is just not as miscible with R-134a. That is why OE prefer it for the OE fill.
Go with the Ester.
Matt
Ken Burton wrote on Fri, 11 September 2015 21:16I always use the correct oil to match what the vehicle had at manufacture time. The way I understand it there are basically 3 types of oil and several weights at least when PAG is used.
1. Mineral oil was used with R-12 and R-22.
2. PAG was sued in most R-134 applications.
3. Then there was Polyester (POE) oil was used where?
Here is why it is important to me.
When I got my coach about 14 or so years ago the PO had switched it to R-134. I left it that way until a hose rubbed through on the frame, leaked, and needed to be replaced. It is interesting that none of the o-rings were switched to green ones. Everyone I have looked at one it is black but never leaked. At that time seeing no oil leaks on the hose I replaced the hose and dryer and added no oil. I charged it with Duracool and it ran well until now when I developed another leak at the front compressor seal.
Now I am removing the compressor to fix the front seal and I'm sure to loose some oil in the process.
I will recharge it again with Duracool so oil type is not an issue there. What is an issue is what type of oil can I add and not cause a problem with what is already in there.
Can I add POE oil and not cause a problem or do I have to guess that the oil still in it is mineral oil and add some of that?
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
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| Re: Refrigerant oil questions [message #287116 is a reply to message #287108] |
Fri, 11 September 2015 23:57 |
gbarrow2
Messages: 765
Registered: February 2004
Location: Lake Almanor, Ca./ Red Bl...
Karma: 3
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Senior Member |
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Ken,
Your questions about various refrigerant oils leads me to another question about the oil and o rings in my newly installed rebuilt compressor.
When I bought my coach it was charged with R-12. Later I charged with DuraCool. Worked fine until recently when my compressor started leaking at the rear gasket (not the O-rings)
Since the system still had the original R12 mineral oil I filled the new compressor with mineral oil.
The old compressor had black O-rings. The new compressor came with green O-rings which I installed. The Dura Cool leaked out overnight. I replaced the O-rings with another pair of green ones, recharged, and it leaked out again.
So, my question is: Are the green R134 O-rings in compatible with the mineral oil? Will I get it to seal if I use black O-rings?
Would be great if the solution is that simple. Should only take the cost of 2 black O-rings and 3 cans of Dura Cool. to find out.
Anybody have experience or input?
Gene Barrow
Lake Almanor, Ca.
1976 Palm Beach
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| Re: Refrigerant oil questions [message #287117 is a reply to message #287116] |
Sat, 12 September 2015 01:50 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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Senior Member |
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I am not an expert on this but I thought that the green ones could be used for both R-12 (mineral oil) or R-134 (PAG) I have never changed mine except on the dryer that I replaced. Those two are green.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: Refrigerant oil questions [message #287121 is a reply to message #287116] |
Sat, 12 September 2015 07:19 |
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Matt Colie
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
Karma: 7
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Senior Member |
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Gene,
A long time ago I was assured by an Oring supplier that the material colors used by manufactures were all manufacturer specific.
All elastomers absorb some of everything that they are near.
Black is usually Nitrile and that has the most absorbance of just about everything.
Green and Blue (the most common colors) can be just about anything, but are almost certainly less absorbent than Nitrile.
Given your account, if both you believe the joint leaked with both green and black seals in place, I would suspect you have an issue other than the seals themselves. When you get back to it, very carefully inspect all the involved components.
When at McCord, I had a small sign that said, "Everybody always blames the Gasket!"
Matt
gbarrow wrote on Sat, 12 September 2015 00:57Ken,
Your questions about various refrigerant oils leads me to another question about the oil and o rings in my newly installed rebuilt compressor.
When I bought my coach it was charged with R-12. Later I charged with DuraCool. Worked fine until recently when my compressor started leaking at the rear gasket (not the O-rings)
Since the system still had the original R12 mineral oil I filled the new compressor with mineral oil.
The old compressor had black O-rings. The new compressor came with green O-rings which I installed. The Dura Cool leaked out overnight. I replaced the O-rings with another pair of green ones, recharged, and it leaked out again.
So, my question is: Are the green R134 O-rings in compatible with the mineral oil? Will I get it to seal if I use black O-rings?
Would be great if the solution is that simple. Should only take the cost of 2 black O-rings and 3 cans of Dura Cool. to find out.
Anybody have experience or input?
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
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| Re: Refrigerant oil questions [message #287125 is a reply to message #287108] |
Sat, 12 September 2015 08:35 |
JohnL455
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
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Is this the 'new' type compressor?? They may use a lip seal with a metal ring much like a mini axle seal in appearance. Usually included with the compressor. The area where the O ring would have contacted is missing and clearanced for a lip seal. Not sure this is your issue but I know for fact new R4s are now this new style requiring 2 sizes of seals and spacers are imcluded for varios applications You use the ones for your manifold and toss the rest. That way one comp fits many applications for them. If you pull the line set you can see if the machined surface for the o ring is there or missing. Considering overnight presssure loss, I'm thinking you may have been just been metal on metal. .
John Lebetski
Woodstock, IL
77 Eleganza II
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| Re: Refrigerant oil questions [message #287127 is a reply to message #287116] |
Sat, 12 September 2015 09:01 |
roy1
Messages: 2126
Registered: July 2004
Location: Minden nevada
Karma: 6
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Senior Member |
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Gene I wouldn't worry about the color of the seal or O rings I would add pressure to the system and soap up the area you suspect has a leak if there are no bubbles present the leak is somewhere else. I sure wouldn't change the O rings if there is no sign of a leak. As far as front shaft seals go I tried a new type seal on a friend's compressor it started leaking shortly after the install. I would probably just use the older type ceramic seal unless the shaft has gotten grooved in which case the new type seal would probably be a better choice because the old type would likely leak for sure.
Roy Keen
Minden,NV
76 X Glenbrook
[Updated on: Sat, 12 September 2015 09:10] Report message to a moderator |
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| Re: Refrigerant oil questions [message #287128 is a reply to message #287121] |
Sat, 12 September 2015 09:45 |
gbarrow2
Messages: 765
Registered: February 2004
Location: Lake Almanor, Ca./ Red Bl...
Karma: 3
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Senior Member |
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Matt,
The black O-rings on the old compressor never leaked. that leak was at the GASKET between the rear plate and compressor body. Leak was out the side- the area around the line attachment never appeared to be leaking.
New compressor"appears' to be leaking only at the a/c line attachment with the new green O-rings.
Is it likely that rebuilders are supplying green O-rings with the compressors with the assumption that R134 and it's relevant oil will be installed since we civilians don't have access to R12?
I'm grasping at straws.
John,
I think the ring/lip seal that you described is a rotating shaft seal. That's not my problem.
Gene Barrow
Lake Almanor, Ca.
1976 Palm Beach
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| Re: Refrigerant oil questions [message #287131 is a reply to message #287128] |
Sat, 12 September 2015 11:17 |
Bullitthead
Messages: 1411
Registered: November 2013
Karma: 5
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Senior Member |
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The ring/lip seal is a washer with a seal vulcanized to the inner diameter. It is used in a connection just like a copper or aluminum crush gasket, like on a brake caliper connection.
Terry Kelpien
ASE Master Technician
73 Glacier 260
Smithfield, Va.
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| Re: Refrigerant oil questions [message #287132 is a reply to message #287108] |
Sat, 12 September 2015 11:55 |
JohnL455
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
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Senior Member |
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Gene, no I'm not talking about shaft seals. Some new compressors do NOT use O rings at the line set to comp body. Total new dedign requiring lip seals and spacers to use your old line set.
John Lebetski
Woodstock, IL
77 Eleganza II
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| Re: Refrigerant oil questions [message #287133 is a reply to message #287125] |
Sat, 12 September 2015 12:07 |
gbarrow2
Messages: 765
Registered: February 2004
Location: Lake Almanor, Ca./ Red Bl...
Karma: 3
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Senior Member |
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John,
Thanks for the clarification.
The compressor is an A6 just like the one I removed and I used the conventional O-rings that came with it. However, I looked at the O-ring grooves on the before and after installing the O-rings. There was a small beveled surface machined around the groove. I wondered about that at the time but no longer had the old compressor to compare to.
It didn't think that a rebuilder would modify a factory sealing surface and the supply the wrong O-ring. But, stranger things have happened.
I can't get to the coach now. I will go to a local NAPA and compare some compressor O-ring grooves if they have any A6's in stock.
Gene Barrow
Lake Almanor, Ca.
1976 Palm Beach
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| Re: Refrigerant oil questions [message #287139 is a reply to message #287131] |
Sat, 12 September 2015 14:08 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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Senior Member |
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Bullitthead wrote on Sat, 12 September 2015 11:17The ring/lip seal is a washer with a seal vulcanized to the inner diameter. It is used in a connection just like a copper or aluminum crush gasket, like on a brake caliper connection.
On the A6 used in the GMC, they are two o-rings seated in two grooves on the back of the compressor
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: Refrigerant oil questions [message #287155 is a reply to message #287132] |
Sat, 12 September 2015 18:59 |
gbarrow2
Messages: 765
Registered: February 2004
Location: Lake Almanor, Ca./ Red Bl...
Karma: 3
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Senior Member |
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John,
I now understand what you've been describing. Since my earlier post today I went to a local auto a/c shop and talked to the owner/experienced tech.
He showed me two different compressors (both newer and smaller than the A6)and the O-rings/seals for each. The first one was as you described- utilizing a flat washer like seal. The other one had a line attachment point just like the A6 and used O-rings.
Then he went to his parts cabinet and selected the O-rings used in the A6 and gave me 2. They happened to be green but he agreed with others here that color doesn't matter.
He pointed out that that the rings are not EXACTLY like normal O-rings. We compared them to other rings in his inventory. The cross section of the A6 ring is not round but more OVAL.
He also said that the rings must sit a bit proud (about 1/64") of the ring grooves in the face of the line attachment point.
He said that if you can't feel the O-ring sticking up out of the groove that it won't compress enough to make a seal.
That sounds like my problem leak. I won't be able to verify for a week or so. Hope it is that simple. And I hope this discussion is helpful to others on the GMCnet.
Gene Barrow
Lake Almanor, Ca.
1976 Palm Beach
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| Re: Refrigerant oil questions [message #287160 is a reply to message #287108] |
Sat, 12 September 2015 21:39 |
JohnL455
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
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Senior Member |
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Ok. I'm glad you think it is solved. Sounds like it. Again, I can't say if they are using the lip seals on A6, but they are on R4s. At least your inquiry led you to a knowledgeable tech and he knew what I was refering to.
John Lebetski
Woodstock, IL
77 Eleganza II
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| Re: Refrigerant oil questions [message #287165 is a reply to message #287142] |
Sun, 13 September 2015 01:27 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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Senior Member |
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So far I have found no evidence of oil anywhere. I have not pulled the clutch and seal yet but I assume that I will loose some oil if I remove the compressor from the engine to do the job. I'm first going to try to replace the seal on the engine. If I can get the seal replaced on the engine then I should not loose any oil.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
[Updated on: Sun, 13 September 2015 01:29] Report message to a moderator |
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