Ok so it's time for me to finally fix my A/C. I haven't used it in probably 3 years now. It is fully charged and last time I used it, it blew ice cold. I stopped using it because I noticed that last time it was used that the compressor would whine like a roots supercharger. I turned it off and on a few times to be sure it was that. I unplugged the pigtail and tucked it out of the way. Fast forward to today and it's time it gets fixed. So I have picked up a good used compressor, orifice tube, complete o-ring kit, and a receiver/drier. All aside from the compressor are brand new parts. What should my next step be?

I have read I should pull all the lines out and flush them? With?

What about flushing all the parts not easily removed?

I know that if I see any metal shavings or black crust on the orifice tube I need to clean the system really well.

How do I make sure the compressor has the right amount of oil? Since it is used how do I drain and refill it?

Just want to do this right... and ONCE. I turned it on quickly 2 days ago and it still blows ice cold and rather quickly so I can only assume it has no leaks still and is full.

How do I proceed from here????

First call around to some shops and see if any of them are interested in recovering the freon from the sysem. Once you have it empty, pull all the parts from the vehicle that you are able to... You should be able to get the hoses/lines, condensor, filter/drier and orfice tube. At this point you can flush each of these parts. You may be able to leave the condensor in and the two lines that are connected to it and flush it that way.

I have a canister that I pour the flush into and has a flexible line and a blower tip with a rubber nozzle that can be presurized using normal air. This makes it easy to blow the flush through the system.

The evaporator should not be flushed unless all the parts have been removed from it such as the orfice tube as the flush can destroy the plastic/rubber parts. After you have flushed it, blow straight air through it to remove any residual flush fluid.

Your A/C sticker should say how much oil is needed in the system, if not you can call the dealer ship and they should be able to help you, or as you take the system from your car you can dump the oil into something and measure it, including your compressor. I usually add 10% more of the recovered oil to account for oil left in the system. When adding the oil make sure you spread it out through the system, place some in the condensor, some in the evaporator, and some in the filter/drier, and some in the compressor, then close up the system replacing all the rubber o-rings and installing your orfice tube.

At this point the best thing to do is pressure test the system. A vacuum test will not always find leaks. The pressure test puts the system at pressure anyway since that is what it operates under, not a vacuum. I have used CO2 by Nitrogen is the best. I use
CO2 because my welder has it. I mocked up some hoses and tubes that I can attach to my regulator and go to my highest pressure setting on the CO2 regulator. IF you have a nitrogen tank/regulator make sure you do not go above @40psi. I then use kids bubble water (soapy water) in a spray bottle and spray all my fittings looking for bubbles. If you find bubbles track down the leak and fix it. Or if not go on to the next thing.

At this poing once you know the system is leak free, a vacuum should be placed on it for at least 20 min. This drops the boiling point and removes water vapor which is the enemy to the A/C system. If you do not have them you can take it to an A/C shop and ask them to do it. Maybe work out a deal that if they get the 134 you get a free vacuum pull on your system.

After the vacuum is done begin putting the freon in. At first without the system running turn the can upside down so that it is installing fluid into the system. Once you get that first can in, turn the system on, and connect your next can keeping it upright and connected to the LOW PRESSURE SIDE (SUCTION) as you do not want to slug the compressor with liquid.

Keeping an eye on the pressures you should be around 35-45 on the low side and @150 on the high side. Make sure when the system is on you have the fan on high and fresh air not recirculating.

Wow! Now that's the kind of detailed info I can use. Thank you greatly!!!:yes:

No problem. I have my students in this exact section right now. We have done 3 cars in the last two weeks, and plan on two more coming up.

I did forget to ask in my last reply...

What brand/type of flush is good? I have heard people recommend just to use Brake Cleaner, but unless I hear otherwise would rather leave that for use as it is labeled.

Is there an actual A/C flush?

Yes, you should be able to go to your local parts store and they can hook you up. It is a pour can, however I have heard of people using brake cleaner. I guess it would take a lot of cans of spray. But you can do it. The flush is meant to be used in a pressured can. You can purchase the refillable cans that I have but its not a cheap alternative, I guess you could get get one of the cans from a parts store to use like with bulk WD40.

The flushing cannister is from kragen/orilies: http://mastercool.com/pages/valve_core_remover.html
part number 91046-A A/C SYSTEM FLUSH KIT

flush: http://shop.oreillyauto.com/ProductDetail.aspx?MfrCode=IDN&MfrPartNumber=CQ10&CategoryCode=3572A

Nice write up Rod!
You're on a roll since you resurrected the AC in the 64. Your students are being taught well. :thumbsup:

Nice write up Rod!
You're on a roll since you resurrected the AC in the 64. Your students are being taught well. :thumbsup:


Thanks in part to you :beers:

I used and recommend Duraflush for the A/C systems.

Yes, you should be able to go to your local parts store and they can hook you up. It is a pour can, however I have heard of people using brake cleaner. I guess it would take a lot of cans of spray. But you can do it. The flush is meant to be used in a pressured can. You can purchase the refillable cans that I have but its not a cheap alternative, I guess you could get get one of the cans from a parts store to use like with bulk WD40.

The flushing cannister is from kragen/orilies: http://mastercool.com/pages/valve_core_remover.html
part number 91046-A A/C SYSTEM FLUSH KIT

flush: http://shop.oreillyauto.com/ProductDetail.aspx?MfrCode=IDN&MfrPartNumber=CQ10&CategoryCode=3572A

Again, thank you!!!

Nice write up Rod!:thumbsup:

Indeed he has. I printed that out and plan to use it as directions!

I used and recommend Duraflush for the A/C systems.

I will look into that one as well, thank you as well!