Need some help from an AC guy, new parts and I have 20lbs of R12 what oil to use, etc

87 WE2

Active Member
Joined
Jun 28, 2002
Stupid question that I don’t have the answer to because I'm not an AC guy.
I am rebuilding the front end of my car and installing a new compressor, lines, accumulator, condenser, seals, & orifice in the process. I have 20lbs of old school good DuPont R12, not the freeze 12 junk.

The car has always had R12, still had a little charge when taken apart but not much due to bad seals. So I should not need any conversion oil, orifice was clean so there was no junk in the system.

I would like to use the R12 I have, with that in mind
I need to know:
What oil to use with the R12?
Where to get the oil if anyone knows?
How much oil to use?
I have read some should some go in the accumulator, and some in the compressor? If this is the case how much in each and what port of the compressor? Does it matter for the accumulator where to port to put the oil in?

I do not plan to charge it myself I will have that done but I wanted to get the oil and put it into the system as I reassemble it.

Thanks for any help. -Ed
 
R12 systems use mineral oil available at NAPA & probably many other parts houses.

Caution: I added the required (12 ounces, I think - look it up in the service manual) to my sestem which had leaked down & ended up with too much, which plugged up the system. It was a can of worms.

Nick Mcale At ArizonaGN, a vendor on this board, was a a big help to me, getting my AC up. I get 37* at left center AC outlet.
 
A little late in the year but you fix it when you want I guess. :) Mineral oil is right on the oil though. As far as putting it together before you take it in don't. Unless you have a suction pump you don't want to instal the accumulator. It's a moisture trap and once exposed to air it will start drawing moisture into it. That is the very last thing you put on just before you start putting the system under vacuum.

As far as adding oil to the parts, most of the oil will go into the condensor and accumulator. Very little goes in the compressor or you can cause damage to it. Fist, make sure whether the compressor has oil in it or not. If it does, drain it out to see how much was added. If it doesn't, pour about a table spoon worth in it and then turn the compressor by hand so that it sucks the oil in. I usually add about 3-4 table spoons worth to the compressor so that it has just enough oil in it not to lock up. If you add more then you can cause a hydralock type situation in the compressor and then you're back to square one.:(
 
Thanks I hoped to finish this sooner but it's taking longer then expected. I can pull it into a vacume I have access to a pump how much of a vacume should I pull it into? Any tips or instructions for that? I figure at this point I'll just put the oil in assemble it and leave it in a vacume if that's ok for the winter and come spring at inspection have it charged.
My goals are right now is to get it back together and drive it a little before winter hits.

The compressor is a new Delco unit it says to add oil so I assume there is nothing in it but I will check to be sure. How much oil should I put In the condenser and accumulator?

Thanks again
 
If you suck it down you will need to do it for at least an hour. The longer the better though. Make sure to flush the entire system out so you know how much oil you're really adding. 12 OZ total and like I said, use it sparingly in the compressor, and split the rest between the condensor and accumulator.

To be honest with you I'd just replace the compressor if the clutch was the issue and drive it until it warms up. Leaving the system under vacuum for that long may cause other issues to come up. The system is designed to hold pressure, not vacuum, so it may ruin the accumulator.
 
Ok thanks for the tips. Is there an outside air temp in which I should not charge it? Maybe before it gets too cold I can charge it up? I'd like to finish the car now so I can take the cover off in the spring am just go but if needed I guess I'll let it go and finish the AC in the spring.
 
I've found that below 70 outside the system won't take refridgerant easily. If it's below 60 it won't work at all. The refridgerant is at such a low temp it's really had to get it to certain temps to flow into the system.
 
Ok well I guess I'll wait till spring to charge it, I had a thought though if I assemble the system and pull it down. Could I put nitrogen into the system for the winter? I have seen the hvac guys do that here at work when we leave a system hooked up and no gas in it, I know it would not take much to do it just not sure if its the same principle with a car vs a commercial split system.

Or I could reinstall the old accumulator leave the system empty for the winter, then come spring I would pour the rest of the oil in the new accumulator and change it out in the spring before I have it charged.
 
Flush the system out completely, put just enough oil in the compressor so that it's protected and then put it back together until spring. I've never tried using nitrogen but it wouldn't hurt the system. Don't put any oil in the rest of the system because the oil will also absorb moisture over the winter. Once it's warm enough then do the rest of the work and everything should be fine.
 
Bringing this back from the dead.

charlief1 I am getting ready to assemble this thing, I never got to finish it last year. I am pretty sure I am going to use this style PAG oil thats r12 & 134 compatible. http://www.amazon.com/Universal-PAG-Oil-8-oz/dp/B0002JMEIA I plan to charge with R12 as I have more then enough.

Just to be clear add oil sparingly in the new compressor, maybe and 1/2 or 1 full oz? Which port in the comp do I put the oil in, does it matter?
I should then split the rest of the oil up between the condenser, and accumulator does it matter which port I pour it into these parts also?

Thanks
 
Bringing this back from the dead.

charlief1 I am getting ready to assemble this thing, I never got to finish it last year. I am pretty sure I am going to use this style PAG oil thats r12 & 134 compatible. http://www.amazon.com/Universal-PAG-Oil-8-oz/dp/B0002JMEIA I plan to charge with R12 as I have more then enough.

Just to be clear add oil sparingly in the new compressor, maybe and 1/2 or 1 full oz? Which port in the comp do I put the oil in, does it matter?
I should then split the rest of the oil up between the condenser, and accumulator does it matter which port I pour it into these parts also?

Thanks

If you plan on using R-12 do not use PAG, get the correct mineral oil. Mineral oil will mix with the R-12 and the PAG will fall out and not lube the compressor properly. It's much cheaper and won't strip the paint off the car if some leaks on the paint as well.

On to the rest now. Put a small amount of oil in the compressor and turn it. You won't use a whole lot so just put it in, turn it a little and do it again. This will move the oil around just enough to make a sucking sound in the compressor. It shouldn't take more than 2 or so OZ. It goes in the suction side of the compressor which is where the bigger of the 2 lines is on the back of the compressor.

The rest is added to the accumulator and condensor and 50/50 is just fine. Once you suck it down to full vaccum for at least 1 hour turn the compressor by hand several turns to make sure there's no loose oil in it that could damage it.
 
Thanks!

Picked up some mineral oil for R-12 at Napa this afternoon, way more then I need but they only had it in quarts.

Had this car since 2001 its going to be nice to drive it with AC for a change!
 
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