Jump to content
Ultimate Subaru Message Board

Recommended Posts

I recently located my ac leak with using green dye and a uv light. My leak is at the exit seal of the condensor. There was no pressure in the system so I went ahead and removed the line between the drier and condensor. I need to replace the orings and was wondering where I can get them and are they a specific type of oring compound? Thanks.

Link to comment
Share on other sites

Hi, most of the auto parts stores carry assorted packs of o-rings specifically made for A/C usage. I'm doing mine also in about a week or two.

 

 

I recently located my ac leak with using green dye and a uv light. My leak is at the exit seal of the condensor. There was no pressure in the system so I went ahead and removed the line between the drier and condensor. I need to replace the orings and was wondering where I can get them and are they a specific type of oring compound? Thanks.
Link to comment
Share on other sites

[...]There was no pressure in the system so I went ahead and removed the line between the drier and condensor.[...]

I hope you've plugged the openings; if the system is open to atmosphere for a while, the desiccant can absorb too much moisture and you may need a new receiver/dryer.

Link to comment
Share on other sites

Yup. I was in Autozone today and they have an assortment pack of O rings right where the r134 cans are on the shelf.

Hi, most of the auto parts stores carry assorted packs of o-rings specifically made for A/C usage. I'm doing mine also in about a week or two.
Link to comment
Share on other sites

buy the generic $3 bag of o-rings like he said. it'll have the ones you need. be sure to oil them before installing, don't install them dry. not sure what you should oil it with...preferrably lubricant from the a/c system, but maybe motor oil, brake fluid may also work.

 

while the system is open, replace at least both compressor fittings and any other fittings you can easily get to (condensor/receiver/drier)

Link to comment
Share on other sites

buy the generic $3 bag of o-rings like he said. it'll have the ones you need. be sure to oil them before installing, don't install them dry. not sure what you should oil it with...preferrably lubricant from the a/c system, but maybe motor oil, brake fluid may also work.

 

while the system is open, replace at least both compressor fittings and any other fittings you can easily get to (condensor/receiver/drier)

Link to comment
Share on other sites

buy the generic $3 bag of o-rings like he said. it'll have the ones you need. be sure to oil them before installing, don't install them dry. not sure what you should oil it with...preferrably lubricant from the a/c system, but maybe motor oil, brake fluid may also work.

Yes, do oil the o-rings, but I'm not sure that motor oil or brake fluid are good choices. They're meant to be lubricated with refrigerant oil; if you don't have any, use something like this: http://www.nationalonlinetools.com/index.asp?PageAction=VIEWPROD&ProdID=28584

Link to comment
Share on other sites

refrigerant oil only. otherwise you will poisin the desecant.

R-12 systems can use mineral-type refrigerant oil, R-134a should use PAG (polyalkylene glycol). I believe there are ester oils that are compatible with either, but check labels.

Link to comment
Share on other sites

Ester oils were used in some early-on 134a systems, but I was always told that they shouldn't be mixed with PAG. You can buy cans of PAG oil in most auto parts stores that sell the 134a refrigerant. Usually it comes in a pressurized can with a fitting compatible with your recharge hose assembly. Just connect up the can to your charge hose, and empty a bit into a clean, dry metal container (an old clean veggie can works well).

 

Use some PAG oil on the O-rings, and throw away (pardon me - recycle...) whatever you don't use as it absorbs water from the air just like brake fluid does.

 

PAG is also the base for brake fluid, so in principle that ought to work, but I don't know that for sure.

Link to comment
Share on other sites

Ester oils were used in some early-on 134a systems, but I was always told that they shouldn't be mixed with PAG.
From http://www.id-usa.com/how_to_faqs_retrofitting.asp :

 

"8. Why does Interdynamics use Ester Oil instead of PAG Oil?

 

 

While both lubricants are used with R-134a, Ester is believed to be better for Retrofit systems because it is compatible with the residual mineral oil left after evacuating a R-12 system.

 

In addition, Ester oil is a preferred top-off oil because it is compatible with ALL PAG Oils and is much less hygroscopic..."

Link to comment
Share on other sites

From http://www.id-usa.com/how_to_faqs_retrofitting.asp :

 

"8. Why does Interdynamics use Ester Oil instead of PAG Oil?

 

 

While both lubricants are used with R-134a, Ester is believed to be better for Retrofit systems because it is compatible with the residual mineral oil left after evacuating a R-12 system.

 

In addition, Ester oil is a preferred top-off oil because it is compatible with ALL PAG Oils and is much less hygroscopic..."

 

This discussion has progressed quite alot. I just want to lube the orings so they dont dry out. New question: does the compressor have its own oil resevoir or is it recommended to add refrigerant that contains oil? If so what is recommended for the Subarus.

Link to comment
Share on other sites

This discussion has progressed quite alot. I just want to lube the orings so they dont dry out.
Yes, but you should use the correct oil, and you haven't mentioned what model year you're working on, etc. I looked back at your previous posts; if we're talking about the '98 OB, use PAG oil or something compatible with it.

 

 

New question: does the compressor have its own oil resevoir or is it recommended to add refrigerant that contains oil?

The oil is distributed in the system as it runs, although much of it is in the compressor. Unless there was a significant loss of oil due to the leak (which usually doesn't happen, but do look for signs of that), there's probably no need to add oil. However, refrigerant oil is hygroscopic and if the system has been open for an extended period of time, it may have absorbed enough moisture to need replacement.

 

You might find the links below useful.

 

http://endwrench.com/images/pdfs/ACTechTips.pdf?PHPSESSID=f79afa671304403610485a3a591893f7

http://endwrench.com/images/pdfs/ACSystems.pdf?PHPSESSID=fb6fe5310b6c38d169e1b7629cb76948

http://endwrench.com/main.php?smPID=PHP::search_articles.php

Link to comment
Share on other sites

If the system has been "open" for any length of time (say, more than 24 hrs), it is ALWAYS a good idea to completely flush it, then put the system back together and hold it under a vacuum for a few hours. That will remove as much water as possible, as well as removing all the hydrated PAG - which turns to an acid when it gets hydrated and wreaks havoc on A/C internal parts, BTW - then add the spec amount of new PAG oil. After that you can fill the system with the recommended amount of 134a.

Link to comment
Share on other sites

If the system has been "open" for any length of time (say, more than 24 hrs), it is ALWAYS a good idea to completely flush it, then put the system back together and hold it under a vacuum for a few hours.[...]

Thanks for clarifying that. When I mention an "extended period of time", I'm thinking of anything significantly more than what's needed to open the system and replace a part or plug the opening(s), which usually doesn't take more than a few minutes.

Link to comment
Share on other sites

If the system has been "open" for any length of time (say, more than 24 hrs), it is ALWAYS a good idea to completely flush it, then put the system back together and hold it under a vacuum for a few hours. That will remove as much water as possible, as well as removing all the hydrated PAG - which turns to an acid when it gets hydrated and wreaks havoc on A/C internal parts, BTW - then add the spec amount of new PAG oil. After that you can fill the system with the recommended amount of 134a.

 

Sorry, not meaning to hijack the thread, but I recently destroyed my Calsonic compressor when I switched from R12 to R134a. The likely culprit seemed to be the incompatibility between the two refrigerant oils. I did not bother to drain the old oil nor change the receiver/drier. Expensive mistake indeed.

 

How does one completely flush the system? Thanks in advance.

 

Pye

Link to comment
Share on other sites

Well, in the special case of an R-12 to 134a conversion, you can't ever FULLY flush old mineral oil out of the lines, and so in that case you should always do the conversion with an ester-based 134a oil. PAG should NEVER go into a system that ever held R-12.

 

Flushing is done with a solvent that can pick up and hold old oil and small corrosion particles in suspension, and the resulting gunk is pushed out of the system by air pressure. You can buy professional a/c flush equipment to do this, or you can buy an aerosol can of a/c flushing solvent. The procedure is to open up the system at a couple of fittings (be prepared to replace those O-Rings once you break the original seal), then to attach the feed hose from either the pro gun or the aerosol can, then spray away! (The pro flush guns require an external compressor.) Once it appears that most of the gunk is cleared out of the system, then force as much of the remaining solvent out of the system as possible with compressed air. Then lube and replace O-Rings, reassemble, and pull a vacuum on the system for several hours to ensure that all the remaining solvent is evaporated. Then fill with oil and refrigerant. Simple, and actually easier than flushing the 4EAT tranny that so many of us have also dealt with!

 

NOTE: Don't try to resurrect an accumulator/drier by flushing -- it won't work. Just consider that to be a piece that you've got to replace. Also, when you flush thru a compressor you'll have to rotate it several times (by hand) to make sure that the flush gets completely thru the compressor body. Same thing is true when you re-charge the system with oil -- rotate the compressor several times by hand before you add the refrigerant, to work that oil thru the compressor. you don't want to leave a slug of liquid in the compressor, or when it first starts up again it is likely to blow an internal seal. That'll usually mean a new compressor is in your future! :-p

Link to comment
Share on other sites

If at all possible, an air compressor used for A/C service should have an air/oil separator, or be an oilless type; otherwise, there's the chance of contaminating what you just cleaned. An air/water separator would be advantageous as well.

Link to comment
Share on other sites

Please sign in to comment

You will be able to leave a comment after signing in



Sign In Now
 Share

×
×
  • Create New...