Correct Refrigerant Oil for r12? - Page 2 - PeachParts Mercedes-Benz Forum

eatont9999 · #16 05-21-2013, 10:08 AM

The compressor will not hold much oil the way you think. What I mean is to add the oil in the lines after you have installed and sealed the lower compressor connection.

Pressurize with propane. You can make an adapter out of a torch head that will connect directly to your manifold set.

vstech · #17 05-21-2013, 10:41 AM

Quote:

Originally Posted by petecooke

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the POE oils are VERY VERY VERY hygroscopic. they do not release moisture at all... even down to 100microns! (never ever gonna get that low a vacuum in a car system!) so you HAVE HAVE HAVE to put in a new drier with the POE oils. DO NOT PUT DRIER IN SYSTEM until EVERYTHING else is done. you want that drier open the minimum amount of time before you start the vacuum pump. and it's NOT a good idea to put the oil in the drier.
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I know this is a very old thread but I need to add oil to my compressor and was wondering why you should NOT add the oil to the receiver dryer? Won't the oil make it to the receiver dryer when the compressor is running?

Dieselgiant adds to receiver dryer but if there's a better option, please let me know.

I'm thinking about getting a big syringe and shooting the oil through the top (low side) line after removing the schrader valve.

I don't think the compressor will hold 8oz of oil. I'm sure some would spill out when I'm re-stalling the 3 bolts.

Also, any recommendations on what type of 500-525 mineral oil to buy?
FJC makes some Automobile Air Conditioning Parts of Tucson Arizona, Century Auto Air, AC Parts, AC Service and Hoses, centuryautoair.com

Thanks.

pete

My information in that old post was concerning 134 and POE oils... I'd just gotten some training in the field and the supco TXV manufacturer was adamant about the procedure for treating systems.
basically, the POE (Poly Oil Ester) has an EXTREME affinity for water, and any water collected will ONLY come out when the desiccant in the drier chemically removes it. pouring the oil into a dryer would draw moisture directly into the mix and drastically reduce the capacity of the desiccant.
for R12 and Mineral oil it's fine to pour 2 or 3 oz into the dryer, and 2 into the condenser inlet, and 2 into the compressor, and 2 into the suction line... just be sure to evacuate the system completely, it'll all make it's way throughout the system.

the best way to add oil to a system is put the dribble of oil into the compressor, then trickle oil into the other sections of the system, until the correct TOTAL volume of oil is in the system. DO NOT OVER FILL WITH OIL

petecooke · #18 05-22-2013, 09:37 AM

Thanks for the info. I followed dieselgiant's procedure a couple of years ago and used bg-frigi quiet. The system was evacuated and opened because the compressor needed to be removed due to an allen bolt being stripped while removing a bad vacuum pump.

The system was blowing cold and ran great. Now, I've been reading that BG-frigi quiet shouldn't be used or only 2oz used in the system. I wasn't planning on flushing the system or replacing the expansion valve since the system was working perfectly.

I plan on removing the compressor and draining it completely. Then replacing the r/d. Then add 8oz of mineral oil, pressurize with nitrogen and pull a vacuum.

There may be a little bit of the BG- frgi quiet still in the system but, since others use 2oz as an additive, I'm not sure it matter if the system isn't flush and it might help.

Would you flush the system?

Thanks.

pete

vstech · #19 05-22-2013, 10:02 AM

How much bg is in it now? Little will b in the compressor, only 2oz will be in dryer. .did u flush the first time? Don't put in 8 oz. Only put in 3, unless u flush coils.

alabbasi · #20 05-22-2013, 11:00 AM

Quote:

Originally Posted by eatont9999

I use 30wt mineral oil.
It can be purchased by the quart at O'Reilly's after about an hour of convincing the clerk you are not looking for PAG or Ester oil.

Holy cow, you must go to the same O'Reilly's that I do!

petecooke · #21 05-24-2013, 02:04 PM

Quote:

Originally Posted by vstech

How much bg is in it now? Little will b in the compressor, only 2oz will be in dryer. .did u flush the first time? Don't put in 8 oz. Only put in 3, unless u flush coils.

I don't know how much is in the system now. I removed the compressor to remove a stripped vacuum pump bolt and then I re-attached the compressor. I did flush the system completely before adding the 8oz of BG.

Maybe I'll just flush everything again. It was mess doing it the first time but it's the only way to know I've removed all the oil.

I'm going to add 8oz of mineral oil. Would you recommend adding any synthetic BG or any other product to the 8oz of mineral oil. If I were to add 2oz of BG, would I then only add 6oz of mineral oil?

I don't have an Oreilly's near me in Balt. MD. I'll have to find some locally. I'll check Advance Auto and Auto Zone.

I see it sold in quarts and gallons. If I buy that much, could it be used a year or 2 later if the bottle was previously opened? Will it absorb moisture from the air once opened?

Thanks for all of your help.

pete

BillGrissom · #22 05-24-2013, 03:52 PM

I bought a quart of Tech Select "Wax-Free Mineral Refrigerant Oil fo All R-12 Automotive AC Systems", PN 59000 & 209500 by SMP, Temperature Control Div on ebay a few months ago, ~$12. I will use a butane refrigerant like Duracool, which has worked well for me in several cars for 10 years. Before this, I bought Ester oil at an auto parts, but decided not to use it after I read that it isn't very good (degrades) and absorbs moisture. After adding oil, spin the compressor by hand to insure you won't dead-head it with oil when the engine runs it.

To pump it down, I first connect to a gas car intake, shut that off, then finish with a hand vacuum pump. Since your diesel has a vacuum pump, use that first. The hand pump takes ~2 min to get down to almost a pure vacuum which I let sit for 30 min. It comes up a bit from outgassing, which I pump down and let sit again. Then I introduce the refrigerant and start the engine to flow in more.