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Discussion Starter · #1 ·
Ok, I've spent hours in the last few weeks reading the forums here and seriously appreciate all the knowledge you all share here.

The AC in my 2003 Focus SE has been out for a little over a year. I traced the problem to the evaporator core which I replaced. (if you are searching the forum for information on replacing the evaporator, I'll say it's doable but you will literally gut your car down to the firewall - the only thing left will be seats. NOT for the faint of heart!) After replacing the evaporator, I talked to a local shop about recharging it and they reccomended replacing the accumulator first (made sense). So I have replace the evaporator, accumulator, suction line, orrifice tube, the section of the liquid tube that connects to the condensor and various o-rings. Phew...

According to chiltons, I added about 3 oz of AC oil to both the accumulator and the evaporator when installing them.

So now I'm contemplating having it recharged or buying a pump and doing it myself. I'm leaning towards the latter as the cost is about equal and I'm worried that after a year if being down, the compressor or another component may give me trouble. If I own the tools, I can repair and revac without dropping the $120 service charge each time.

Ok, so here is where I am lost, I have followed the AC thread, but since I've added so much oil to both of those components, I'm wondering how in the world I figure out how much oil is in the system and if it's the correct amount. (the stickers are worn off my engine bay) Does the vacuum process remove all the oil I added?

Any advice would seriously be appreciated. And if you find this post down the road, please feel free to contact me about the evaporator replacement process - I'll see if I can talk you out of it ;-)

Ed
 

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ok that system holds 7 oz of oil if you have added 6 oz you should be close. When you vacuum down the system it can remove a very small amount of oil. Now for the down side, it is illegal to vent the 134a to the atmosphere. you could rent or borrow a vacuum pump and vacuum and charge your system but if there is any other problem and it needs to be evacuated you should go to a shop and have that done. then perform the repairs yourself. If you decide to vent it that is up to you I don't know how you would even get caught, and if your not licensed I don't know what the fine would be. I have mine and its either 10k or 20k plus possible jail time.

also if you kept your system closed(no open lines) for the year that its been down you should be ok with the other components.
 

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Discussion Starter · #3 ·
Yikes 10-20K!! I unintentionally vented mine to the enviroment over a number of months. The hole in the evaporator core basically leaked all of the coolant. I recharged it and it lasted for a day or two.

When I disconnected the fittings in the system, I did get a small blast of air and oil, but not refridgerant (as far as I could tell).

So if I put 3 oz (or ~90ml) in each component that I replaced, is there any oil left in the compressor or condensor (which I did not replace)? Then do I understand correctly that I don't need to do an oil charge but can go right to the refridgerant? After vacuuming that is.

I keep wishing for a dipstick!

Thanks for the help focustech - it's much appreciated.
 

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sorry for the late reply, yes there will be oil left in the compressor and condensor with the amount that you added you should be right at the right amount. you should be ready to vacuum it down and wait 15 min for it to remove all the moisture that might be in the system. then charge it up, it should hold 27 oz just a little over 2 cans. just go slow with the cans they can take awhile for the car to suck the whole amount in.
 

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Discussion Starter · #5 ·
Focustech,

No problem on the delay and sorry for my delay in posting an update. I've been out of town for work.

But as an update: I got the system all charged up and despite a few newbie mistakes (just stupid stuff), it seemed to work out pretty well. I drove the car this week over 1000 miles and it was ice cold and given the heat, I was pretty thrilled with that! I had it charged to 38psi at idle and the vent temp was around 51 degees. I was thrilled!

My compressor is making quite the racket - I wondered if it wouldn't being without a charge for that long. But I figure I'll run with it and deal with that down the road. I am wondering if I over charged the system as I am hearing the compressor short cycle at highway speeds. So later this week I'll break out the guages again and see what I can learn.

But seriously, thank you for taking the time to answer my questions... your advice was invaluable to finishing up the job.
 

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If I'm correct, your system is probably still under charged. Your A/C should be blowing around 40 degrees. And your compressor short cycling is another reason why I'm coming to this conclusion. Hopefully you can get this all figured out.
 

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Loose oil is good for oiling up O-rings before making the connection. That's about it. If you vacuumed the system correctly, which is running the vacuum pump for about 30 mins or longer, then disconnect the pump from the gauges with the valves all closed. Reconnect the gauges with the center hose sealed off, and open the gauges to read what remains of the vacuum. Observe the new vacuum reading, and allow it to sit for 30 mins or so. Check the gauges, and see if the vacuum is reduced. If it is, you have a leak.

Short cycling is the LP switch or HP switch cutting the compressor off to prevent damage or icing of the evaporator. You have to figure out which one it is. Most likely it's not the HP switch. Most likely you're a little low, but don't think adding refrigerant will lower your evaporator temperature because it doesn't work like that. AC system efficiency is measured by how much it drops the temperature from ambient. If your ambient temp is 90F, and you've dropped to 51F, that's a considerable drop. Think of it this way: Low side pressure in PSI = evaporator temp. It's not that exactly, I think 25 psi= 32F, but you get my point. Increasing pressure to prevent LP cycling will increase your temperature- BUT a correct charge will insure proper oil circulation and operation of the system.

I personally think that you vacuumed out more oil than you think you did, and that's why the compressor is making noise, but I'm unsure if you can get away with adding a full 3oz can of compressed oil. I guess I didn't stress using compressed oil only to DIY recharge enough in the General AC thread.

At this point I think you should find a local shop that will work with you and put your vehicle on their machine to insure you have the correct blend of oil and refrigerant in your system. I'd go early in the morning and talk to them, and explain what has been done. They have a machine that will circulate your refrigerant and oil and add what is needed. You either have slightly too much oil or slightly too little refrigerant, but you certainly don't want too much refrigerant or too little oil.
 

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is the compressor making noise all the time like bad bearings, or is it only making noise when its engaged, or only after its been engaged for a period of time? also ifs its cycling at highway speeds I would suspect underchared? what process did you use for charging the system and how much did you get in it?
 

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How about a compressor that never turns off? i noticed it will always spin at an idle, if i blip the throttle it will turn off and back on when at an idle. that doesnt make sense because while driving it works fine so it has to be still running.

While filling it up, of course it had zero oz so it didnt cycle at all. 1 10 oz can it started short cycling. another 10 oz can and it gets longer and longer cycles. the 3rd 10 oz can (remember the plug is in a stupid location so every can i add i probably release an oz.) it is cycling all the time.

My only a/c problem is 1, its cold but not uncomfortable like a good working a/c should be. (when it works) (might be 1-5oz off of system capacity)

and 2, it will sometimes stop blowing cold air for whatever reason. i swear i smelled freon and the air is humid. it will eventually go back to normal. ideas?


Ill be taking it to a shop to see whats up.. hopefully its not expensive.
 

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^^^
sitting still idle it up to between 1500 and 2000 rpms and see if your cycling, I would suspect you are still undercharged.
 
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