Is AIr con recoverable?

[sproutdreamer]

The Yaris Aircon has not worked for about a year due to a leaking condenser radiator revealed when garage tried to fill up aircon system and it did not hold pressure. It has been kept switched off in that time. My understanding is that seals "dry, become hard and lose their sealing capability" when the system loses the fluid which contains seal conditioners etc.

I do not want to go to the expense and work of fitting a new condesor and fluid recharge if the likelyhood is that the system will just leak and lose pressure due to the seals losing their sealing ability. So my question is whether members have experience of succesfully re-commissioning car aircon after a substantial downtime or whether |I would be wasting my time trying to retrieve a working system.

I understand how aircon works and I can guess & theorise about this like everybody else but I am looking for actual experiences of this situation to help make up my mind what to do. Thanks as always.

[flash22]

Thought I had read this before, as before pull a vacuum on the system if it will not pull a vacuum it needs a test charge with a uv dye

 

[sproutdreamer]

Well spotted Flash. I am still dithering over this as it seems that I cannot find if the seals are shot until I have replaced the leaking condensor/drier unit and had it professionally vacuum tested, some work by me and about £140 and then filled with gas. I was just looking to see if anyone had ben down this road and how their aircon turned out afterwards. As my daughter now has the car I would like everything to work as it should so I will have to suck it and see.

[Auris James]

I have a 1996 Volvo 940 and wanted to recommission the AC 3 years ago. Old workhorse with 184,000 miles then. 

The condenser was well rotten. Was a mare to remove the clamp that secures the ac pipes to the condenser. After lots of hammering, chiselling, drilling got it out. Bought a Nissens replacement condenser. Fitted great. Went and pressure tested  but compressor was hissing badly. Bought a used compressor from eBay for £30.00 and had it fitted and re-gassed.

Lovely cold AC! Lasted around 8 months! Leaking at new O rings on condenser clamp and clamp not in good order as damaged a bit in removing. No longer available in Europe but available in America, but not compatible.

For the last 2 years not bothered as had other car with AC. Finally found a good used AC clamp and am going to refit with new O rings and get it working again. At least it has R143A refrigerant.  So yes I'd say expect issues. The seals will hopefully re-swell and be ok. Fitting any of the parts was expensive as most garages said don't bother and quoted crazy labour rates.

James.

[Mooly]

One big problem is that the oil in compressor (which is where most of the oil resides, only a small fraction circulates at any one time) will become acidic when exposed to atmospheric moisture. It is a recognised issue.

Some manufacturers of these special PAG oils (Poly Alkylalene Glycol) recommended they be discarded after only an hour or so exposure to the air.

http://pmmonline.co.uk/technical/ac-systems-why-do-they-need-the-right-compressor-oil/

 

 

 

[sproutdreamer]

Thanks for the link and comment about oil. Even having read the link I am still hazy about the role of the oil and exactly where it is in relation to the refrigerant? Does it mix with the refrigerent and circulate or is it held seperately in a reservoir in the compressor?

[Mooly]

The oil is added to the compressor when the system is built up originally. Some compressors have a sump and an opening where the first fill of oil is introduced whilst others have no sump as such. The amount of oil isn't much, just tens of millilitres not large quantities. In both, most of the oil remains in the compressor at all times  

The refrigerant naturally picks up some of this oil as it is pumped around the system but the quantity circulating with the gas is quite small, the vast majority remains in the compressor which needs to be well lubricated at all times.

Knowing how much oil is in a system is pretty inexact. None should be lost but small refrigerant leaks mean that some oil will be lost and it's normal for a small quantity of fresh oil to be reintroduced along with new refrigerant when performing routine regassing etc. The only way to know for sure what is in there is to drain each part and add up the amounts recovered. 

 

[sproutdreamer]

Thanks for the explaination, I understand now.