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Correcting a mistake

mlelah on Sat April 17, 2010 10:50 AM User is offline

Year: 1989
Make: Honda
Model: Prelude
Engine Size: 2.0
Refrigerant Type: R12/R134A
Country of Origin: United States

I know I made a mistake. I did not flush the old R12 oils from my system when I replaced my condenser and compressor. Everything is hooked back together again and I have not run the a/c. I can see that a little oil has dripped into the compressor from the hose/connector. What is my best course of action now? I want to do this right. Thanks.

iceman2555 on Sat April 17, 2010 1:14 PM User is offlineView users profile

Probably what you do not wish to hear, however, to complete the repair properly.....remove the system and thoroughly drain/flush all components. This is the only method to insure removal of all residual lubricants. Many may say simply use POE/Ester lubricants, they will mix with the mineral lube and thus no problems. However, the AC system is only' XX' number of cc's in size. This system is designed to be charged with a certain amount of lubricant and refrigerant.
This vehicle utilized a Matsushita/Panasonic NL1300AA4 Compressor Rotary vane compressor. This unit is very susceptible to over lubricant charges. The compressor does not employ a standard reed valve assembly but utilizes a 'modified' trap door type control device to control refrigerant flow. The internal rotations of this compressor employ many degrees of metal to metal contact of the vanes to the compressor body. Excessive lubricant (liquid) that may migrate into the compressor will result in severe vane damage.
The normal system lubricant charge is 5 oz. If this amount is not removed and an additional 5 oz is added to the system, the possibility of lack of system performance and system damage is greatly enhanced

Actually to complete this repair properly and your statement to do this job right, the system should be cleaned completely, add correct amount of new lubricant, evac and recharge with R12. But then no one wishes to hear the R-12 issue any longer. Your system will operate and cool more efficiently with R12 vs 134a. However, if you were to replace the condenser and modify the engine cooling system to accommodate the excessive liquid line pressures of 134a, then the system could be made to work very well. However, the cost of this modification would greatly exceed the cost of the R12.




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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.
Thomas Jefferson

mlelah on Sun April 18, 2010 4:59 PM User is offline

OK. I understand the issue of the oils. And you are correct about the compressor type. The info that came with the compressor says that it was shipped dry. Would it be a good assumption to assume this is correct? I presume the condenser and new drier were also shipped dry. I did use an R134A oil from a compressed can for the o-rings but not sure which one. I can go to the store and see because I know what I bought. I presume some of the oils still in the lines dripped into the compressor and condenser. As I said I do want to do this right, but I'm not sure what to do. But, except for the small amount of oil I used to lubricate the o-rings, the only oil in the system should be the residual R12 oil still in the lines. Can I flush everything (what should I use)? It's not clear why I should dismantle and if I dismantle what should I do? Thanks

iceman2555 on Sun April 18, 2010 5:20 PM User is offlineView users profile

Your statement initially indicated that the system had not been flushed and that the mineral lube remained. However, if the system was flushed and clean properly, there is no need to dismantle the system. The amount remaining in the hoses will be of no consequence, unless the lines have filter/mufflers. ( I do not think this vehicle was so equipped.).
The compressor should have a max of two oz of lube added to the suction side. The rec/drier max 1 oz. The remainder could be added to the evaporator.

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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.
Thomas Jefferson

mlelah on Sun April 18, 2010 6:10 PM User is offline

Sorry, the system has not been flushed. I installed the new components. As I said I believe that the components were dry. Can I now flush the system, then add the correct amount of new oil, and the charge? I don't understand the why I would need to dismantle. Thanks.

HECAT on Mon April 19, 2010 6:19 AM User is offline

Quote
Originally posted by: mlelah
Sorry, the system has not been flushed. I installed the new components. As I said I believe that the components were dry. Can I now flush the system, then add the correct amount of new oil, and the charge? I don't understand the why I would need to dismantle. Thanks.

Read the article listed in my signature.

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HECAT: www.hecatinc.com You support the Forum when you consider www.ackits.com for your a/c parts.

FLUSHING TECHNICAL PAPER vs2.pdf 

NickD on Mon April 19, 2010 7:14 AM User is offline

Poster states, R12/R-134a for the refrigerant, is this a conversion? If so, would make darn sure its flushed out and that the receiver is R-134a compatible if he wants it to last longer than a couple of weeks. And use an R-134a compatible oil. With Honda's best to stick with Honda oil, fussy suckers.

mlelah on Mon April 19, 2010 10:51 PM User is offline

Thanks Guys. I'll read the flush article and then let you know if I have any more questions. Got it about Honda oil.

mlelah on Mon April 26, 2010 8:43 AM User is offline

OK, I've read up on flushing and I know I need to flush the system. Please let me know if the steps I'm proposing are correct:
1. Disconnect and remove the compressor. Flush with R-134A oil according to the procedure outlined in http://www.autoacforum.com/messageview.cfm?catid=20&threadid=12050
2. The condenser is new but could have been contaminated with R-12 oil drippings from the hoses. Disconnect and reverse solvent flush.
3. Disconnect the hoses and reverse solvent flush the hoses and evaporator system separately.
4. What do I do with the drier? It is new but also could have been contaminated with R-12 oils drippings from the hose connections.
Remember that I'm looking to convert to R-134A but my mistake is that I did not flush out the R-12 oils before installing new condenser, drier and compressor. I have not run the system. Thanks.

HECAT on Tue April 27, 2010 6:20 AM User is offline

1. The compressor oil flush is a good plan, even with a new compressor. This eliminates the concerns of how much oil was in there for shipping, what type of oil was in there for shipping, and did that oil become contaminated during storage and shipping.

2. Since the condenser is new and system has not been run, I would not think this component needs to be flushed. But if you do, make sure you can get all the solvent out and the component is completely dry and not contaminated with flush.

3. You will need to remove the TXV to flush the evap and hoses. Again, it must be dry when you are done.

4. The dryer is probably still good to use. That is if it has not been sitting open for a while and is a 134a compatible unit. There is no option here but to replace if you are concerned or unsure.

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HECAT: www.hecatinc.com You support the Forum when you consider www.ackits.com for your a/c parts.

FLUSHING TECHNICAL PAPER vs2.pdf 

NickD on Tue April 27, 2010 6:55 AM User is offline

Could add, or maybe shouldn't add, you won't be happy with R-134a, will never get a clear sight glass without exceeding system pressures. But I have to admit to never trying a parallel flow condenser. These systems were marginal to start with, even with R-12, really never was happy with the many Honda's in the family in terms of AC or heating during this era. System can be filled with less than two cans of R-12.

mlelah on Tue April 27, 2010 7:59 PM User is offline

Thanks for your careful suggestions. I'm getting all the pieces together and will soon start to do this. I know that the R-12 system was marginal - and I guess the R-134A system will be less so, as you predict. But I'm looking to get some moisture out on those hot muggy days, and/or use for defrosting. The prelude has great ventilation - sun roof and windows open is a lot of fun.

Last question - for flushing the compressor, and filling with oils - when I go to my Honda dealership to purchase the oil - how much should be enough? Thanks.

NickD on Wed April 28, 2010 3:23 AM User is offline

Never could get from Honda the full specified quantity of oil for their systems, would say add so much if you replaced the receiver or the condenser, or the evaporator, but would only say their compressors came with oil, so don't add any when replacing that. Kind of guessed the total oil to add to a dry clean system was about 5.5 fluid ounces.

Also do not recall reading about anyone that converted to a parallel flow condenser, but do recall many saying very unhappy results when attempting to use R-134a in these systems. Your car has a high side dual function switch that kills the compressor if outside of a 40-430 psi range, seems like hitting above 430 was quite common with R-134a. Only to correct that was to remove refrigerant to get even more bubbles in the sight glass, bubbles don't cool very well.

mlelah on Wed April 28, 2010 11:43 PM User is offline

You seem to be telling me to clean out the system and then go back to R-12?? I guess I could do that, but will auto repair shops fill with R-12?

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