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How do I seal the system while I'm working on it?

ozone on Fri September 25, 2009 12:49 PM User is offline

Year: 2002
Make: Toyota
Model: Solara
Engine Size: 3.0 V6
Refrigerant Type: R134
Ambient Temp: 90 F
Country of Origin: United States

Here's the situation:

I am swapping a V6 engine into my 1988 Corolla GTS. The donor car is a wrecked 2002 Toyota Solara. The car runs and drives and the air is ice cold. I plan on swapping the entire a/c into the Corolla as well. Unfortunately to do so I have to crack it open, which means I will lose my seal against moisture. I live in Florida and it is very, very humid here. Plus it will definitely take me months even years to get to the point where I'm ready to fill up the system and start running the a/c.

So the question is, how can I ensure that the system won't be destroyed by moisture or old age while I'm working on the rest of the car? I believe I could probably come up with some kind of plugs or plates with a seal to seal up the system, but face it, once it's open, there's air in it and even if it's sealed, that air will start killing the system.

I have at my disposal CO2 or a CO2/argon mix from my welding equipment. Can I try to fill the system with one of these gases while it sits? They are inert and should not react with anything I believe, but I'm just not sure.

I am correcting a previous swap that "didn't take." When I did that one I had an a/c shop get the air going (original R12) and it cost $1200! It was done during the fall, when the weather wasn't bad. I used it maybe half a dozen times over the course of a year (the car didn't get driven much) and the last time I tried to use it, it didn't work. I brought it to the shop and they said the compressor leaked. They blamed it on the compressor being over-rev'd. I believe that is crap, since the first 14 years of ownership, I red lined the engine many times with the air on and the old system didn't die. My theory is that the remanufactured compressor sucked. I've heard in general that they do, but a new one wasn't available. Anyway, at these prices, I believe I am going to start doing my own a/c work. I'm sure I can find the procedure for evacuating and refilling the system on this website and all the tools I would need, but I didn't see the answer to this question. I apologize if I missed it and I welcome any opinions of remanufactured a/c compressors.



TRB on Fri September 25, 2009 3:45 PM User is offlineView users profile

Best to flush the system per the Hecat tech paper. Sure you can cap it off but it's best to start fresh in my opinion.


When considering your next auto A/C purchase, please consider the site that supports you:

Chick on Sat September 26, 2009 7:03 AM User is offlineView users profile

And when you are ready to charge the system, a NEW drier is needed.. Keep the compressor well lubed while storing it also..

Email: Chick


Freedoms just another word for nothing left to lose

maillemaker on Sun September 27, 2009 9:20 PM User is offline

Hello Ozone.

Bear in mind, I am not an AC professional, and I have only been reading on this subject in preparation for learning to do my own AC work for about a month. I did pass the Section 609 certification exam, but that's not terribly difficult given that the test is open book and unlimited time.

My understanding is this:

When you "crack open" any automotive AC system, you must replace the receiver-drier and/or accumulator. These devices have desiccant in them that remove trace amounts of moisture from the system. But they can only handle trace amounts and once opened to the atmosphere they are ruined by absorbing their entire capacity within a matter of minutes. This is why these units must be replaced when the system is rebuilt.

Once you crack open the system, you can assume that full atmospheric humidity has entered the system. As long as you plug any open hoses to keep out debris, I believe you should be fine. It does not matter if atmospheric moisture enters the system while you work on the rest of the car as you are going to: 1) replace your receiver-drier and/or accumulator during the AC rebuild and 2) you will draw a vaccum on the system to boil off any internal moisture before recharging the system with the appropriate lubricant and refrigerant.

It appears to me that in order to work on automotive AC systems what you need are a good set of AC gauges and a vacuum pump. You need special, likely expensive equipment to reclaim refrigerant already in the system as you cannot just vent it to the atmosphere. You will also need an accurate (to within a half-an ounce, I'd say) scale to be able to keep track of how much refrigerant you are putting into the system.

I'll let the professionals chime in here with corrections.


maillemaker on Sun September 27, 2009 9:22 PM User is offline

Oh, to clarify, you will either have an accumulator or you will have a receiver-drier, not both.


iceman2555 on Sun September 27, 2009 11:18 PM User is offlineView users profile

Since the AC components for this swap may be in storage for several months...even makes not that the moving part...the compressor is lubricated and protected to prevent possible rust accumulations. Why not simply remove from the vehicle....drain all the OE PAG lubricants from the compressor, discard this residue. Personally, I would fill the compressor with a MINERAL AC lubricant. This will prevent possible moisture contamination if either PAG or POE lubes are used as storage medium. Fill the compressor completely...rotate the clutch driver (the very front of the pulley assembly) to insure adequate fill and coating of all internal parts. This lube will also keep the shaft seal protected. Seal the ports to prevent possible spillage of lubricant.
Once the vehicle goes back together simply, drain the compressor...add the appropriate lube (PAG) (3-4 oz and rotate compressor as this several times to insure removal of as much of the mineral lube as not worry if not all of the mineral lube is removed...the small amount remaining will not result in harm to your system....drain once more and then add the correct amount of PAG for final assembly.
The REC/DRIER should be replaced. Do not throw it away...not may need to physically match it in the future.
The hoses can be stored in a plastic container.....some of the vacuum seal bags found at home ware stores are good for this.
The evap can be stored the same way. If not in bags, simply place it in some type of container with a sealable top and store it. Drain the evap to remove as much residual PAG lube as possible....if desired coat the inside of the evap with mineral lube also. It can be cleaned out later.
The TXV should be replaced. Once more save it for possible match up in the future. Simply place the TXV and RD in the box with the evap.
The condenser can be stored in much the same way as the evap. A cardboard box of sufficient size for this part should be acceptable. If concerned about possible aluminum degeneration, simply coat with a light weight mineral lube. Something that could be easily removed, perhaps with simple green etc. Seal the ports to protect from possible debris ingestion.
Mark all boxes.
The major concern would be to protect the parts from physical harm.
When ready for final installation, purchase the new parts necessary....clean the storage chemicals from the parts....flush the evap and condenser and reinstall.

The strongest reason for the people to retain the right to keep and bear arms is, as a last resort, to protect themselves against tyranny in government.
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ozone on Sat October 03, 2009 8:55 PM User is offline

Thank you for all the replies. I knew about replacing the drier, just didn't mention it.

I was wondering, why not just fill all of the components with the same oil used in the compressor (PAG?)? Then just drain them all when I'm ready to reassemble. I could just add a little bit less lube when it's refilled to account for whatever is left in the system.

Also, it looks like I'll probably be replacing the condenser, since the car was hit in the front and it is sort of twisted. It's incredible that the AC still works, but it works quite well.


Edited: Sat October 03, 2009 at 9:01 PM by ozone

Chick on Sat October 03, 2009 10:40 PM User is offlineView users profile

Pag oil is hygroscopic and unless the system is sealed it will absorb moisture.. So if you fill it with PAg you need to remove it before charging the system anyway.. Mineral oil is a good idea, and ester would be the second choice.. Use only fresh pag when charging the system..But drain any oil you use before assembling the system and always use fresh oil when you're ready to charge the system.. Hope this helps..

Email: Chick


Freedoms just another word for nothing left to lose

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