Freon leak

Old 11-12-19, 01:40 PM
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Freon leak

I have a mini-split system that's about 5 years old and that worked fine until this past summer when I no longer got any cooling out of it. All components of the system work fine so I figured the freon charge sprung a leak. I called a local repair firm to come look at it and he gave me some astronomical figure just to look at it and find the leak. He also told me he could replace it for a price that was about $1500 above what I paid for it. I installed the system myself except for the freon charge. Since I feel he was overly expensive I thought I would try to find the leak myself, fix it, then get someone to come here and recharge it. The freon line goes from the outside unit about ten feet to the split hanging in my bedroom. I am either going to try to find the leak myself or perhaps order a new charge line and replace the old leaky one. I have a maintenance background but a.c. repair has never been my best virtue. Is there a certain method in trying to find the leak? My first thoughts are to try to find something loose or a pin hole in the line. Thanks for any help you can give.

Old 11-12-19, 02:18 PM
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Not sure if this topic is allowed to be discussed so if not, sorry mods, just delete my response.

If your sure it's out of refrigerant, look for a coating of oil somewhere on the line, evap or condenser. Often times this will indicate the area of the leak. If nothing found, I would put a positive charge on the the system with nitrogen then essentially spray areas with a strong soap solution to locate bubble. Note that the bubbles could be very small, very very small.

Hopefully it would be at a connection you could tighten. If it's a hole, I know you close it with solder, but I've never done it and not sure of the technique.
Old 11-12-19, 05:00 PM
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Thanks for the reply. I am sure it's out of refrigerant not only because it doesn't cool but that man that came in to check it told me there's none in it. I don't want to pay his sky high costs so I thought I would try to fix it myself. Thanks again.
Old 11-12-19, 05:56 PM
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This site doesn’t allow discussion or instruction on charging or topics related to it.
But I will say, if it’s empty, you aren’t going to find a leak very well.
There’s no reason to start replacing random parts like the lineset without knowing where the leak is.

Last edited by roughneck77; 11-12-19 at 06:20 PM.
Old 11-12-19, 07:55 PM
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I installed the system myself except for the freon charge.
That would point to loose connection since they aren't soldered.

As mentioned we can only offer limited help on your problem. You really need to get a tech in to put a nitrogen charge on it to look for the leak. Don't change the lineset without confirming where the problem is as it could be in one of the coils. I've worked on several systems where the leak was at the threaded fitting.
Old 11-12-19, 11:44 PM
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Go to YouTube, they have many Freon leaks videos.
Old 11-16-19, 10:58 PM
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for it to have no refrigerant left, the leak is probably large.

we can't talk about charging with refrigerant etc, but there's nothing stopping us talking about finding a leak without refrigerant...

The system can be charged with nitrogen and then a leak detection fluid can be used.

Keep in mind if you bought an el-cheapo diy system it probably has low quality paper thin copper coils and you may be screwed - the same copper used in disposable window a/cs and dehumidifiers.

in the us it may also have quick connect fittings (particularly if all you had to do was screw the lines together - no vacuuming/charging) and they're more likely to leak than flared or soldered connections.

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