AUTO A/C FLUSH

Jack345

Member
Was going to flush my A/C system until I read the instructions it states "DO NOT FLUSH COMPRESSOR, EXPANSION VALVE, FILTER DRYER OR ACCUMULATOR". I need schooled on flushing an air conditioning system... I was under the impression that the whole system was flushed with a flushing agent allowed to dry with compressed air then was ready for oil , vacuum & refrigerant ? Correct way is? Is there any alternative to the $16-25 a qt parts house flush. Thanks
 
The reason it would need to be flushed is to remove anything that came out of a failed compressor.

The filter/dryer would need to be replaced, the expansion valve/orifice would need to be removed.

Then while the system is disassembled, all the hoses, evap, and condenser would get flushed. Once flushed, then the new compressor, filter/dryer, expansion valve/orifice tube would be installed, system vacuumed, oil added, charged with refrigerant.

Flushing is extremely important! You can blow it with air before it's flushed, but the final cleanout should be with nitrogen. It's very difficult to get every trace of contaminate out of a system, and no way to tell if it's all out.

This is my most dreaded job! One of those decisions, do I DIY it and take a chance of missing some contamination and having it ruin the new compressor? Do I take a chance on getting a bad compressor, then get denied warranty because I get blamed for not getting it clean?

Or do I just take it to a reputable shop so if there is a problem they have to deal with the warranty?

Tough decision!
 
You only flush the lines, condensers and evaporators when you do an A/C flush. The components that say DO NOT FLUSH are replaced or should be replaced in conjunction with a flushing. The reasons why these components can not be flushed are: 1) it either near impossible to do or guarantee that you got them 100% clean, 2) these parts are already ruined if you had a catastrophic failure (compressor shelling or filter decinegrating), 3) or the flush will cause premature failure. As far as how a system is flushed you are correct, pour some flush in and blow it thru with compressed air. I do not know an alternative to the $16-25 flush. I know its pricey but on the plus side you only need to use it when you have a catastrophic failure at which point whats another $25 on a $500 bill.
 
(quoted from post at 10:13:55 07/25/15) Was going to flush my A/C system until I read the instructions it states "DO NOT FLUSH COMPRESSOR, EXPANSION VALVE, FILTER DRYER OR ACCUMULATOR". I need schooled on flushing an air conditioning system... I was under the impression that the whole system was flushed with a flushing agent allowed to dry with compressed air then was ready for oil , vacuum & refrigerant ? Correct way is? Is there any alternative to the $16-25 a qt parts house flush. Thanks


What are you working on and what is the issue...
 
I'm working on a older Volvo with over 300,000 miles I noted that some of the "O" rings in the A/C system were getting checked they were the old black rubber ones. I have a low mileage parts car that better parts are being removed & installed on the wagon. No A/C failure just routine maintenance,and as long as I had system apart though a flush was a good idea...having second though on that now. Thanks for all the replies.
 
(quoted from post at 21:32:01 07/25/15) I'm working on a older Volvo with over 300,000 miles I noted that some of the "O" rings in the A/C system were getting checked they were the old black rubber ones. I have a low mileage parts car that better parts are being removed & installed on the wagon. No A/C failure just routine maintenance,and as long as I had system apart though a flush was a good idea...having second though on that now. Thanks for all the replies.

If the compressor did not tear up I would not flush, if it did are shows sighs of contamination it gets new hoses, condenser, accumulator/filter dryer and expansion device...

About the only thing left to flush would be the evaporator and its rare I flush those it depends on how the system died... In your case I see no reason to flush if I did it would be so you would know how much oil to put back in it... In your case I would roll the dice and make a educated guess on the oil... Its a Volvo it may as well be a tractor we still dunno what type of system it has...
 
If it is already a R-134 system, and does not have parts of a failed compressor floating through the system, there is no need to flush. Replacing the o rings, etc sounds like a good idea. It would probably not hurt to add 2 ounces of the appropriate ( ester, PAG) oil to the system when you recharge it. If it has added 'Freon' added over the years, it has lost some oil as well. Make sure your fan clutch or electric fans work as they should, for good low speed air flow over the condenser.


Garry
 
(quoted from post at 11:56:52 07/25/15) A case of "If it ain't broke we'll fix it 'til it is"!
ob sure has that right! Luckily, most people can't find the flush handle on their A/C unit. :twisted:
 

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