A/C Recharge
#1
03-19-2012, 01:43 AM
Join Date: Jan 2009
Location: Eastern Central New York State
Posts: 1,003
A/C Recharge
This is probably a dumb question, but I had to recharge my A/C system because it always loses charge over the winter due to a slow leak I can't find. How do I tell if it is full? I added 3 cans and the pressure moves between 25 and like 50 at idle with the compressor cycling on and off every few seconds. I added another can tonight and it was pinned at like 20-25 at idle at 68 degrees with the compressor on continuously. After I added the freon I noticed the big silver "can with the hoses" (Don't know what it is called) that has the low side port was covered in frost. Did I put too much in the system?
By the way, all these pressures is with the A/C on max cold and full fan.
EDIT: I also put a small can of PAG 150 oil in there before adding the first can. I do that every winter or any time it runs out of freon completely to prevent any compressor problems. Only compressor noise I ever hear is the initial "click" when it engages and while I can feel the minor drag when it is engaged while I am driving, I don't hear any grinding or anything like that.
By the way, all these pressures is with the A/C on max cold and full fan.
EDIT: I also put a small can of PAG 150 oil in there before adding the first can. I do that every winter or any time it runs out of freon completely to prevent any compressor problems. Only compressor noise I ever hear is the initial "click" when it engages and while I can feel the minor drag when it is engaged while I am driving, I don't hear any grinding or anything like that.
Last edited by ComputerNerdBD; 03-19-2012 at 01:47 AM.
#2
03-19-2012, 05:56 AM
When i did mine the cans came with a gauge on them that told you when you were good to go.
Prob a site somewhere with the values
Prob a site somewhere with the values
#3
03-19-2012, 07:21 AM
Your descriptions are too vague..
The oil. Do you mean the standard size cans with 134a + oil. Or the smaller one that just is oil with a refrigerant charge {it says to hold upside down I think}. Also slow leaks rarely lose much oil so I'm pretty sure you have too much oil in it. I would suggest you change your accumulator next time.
And by 134 cans I assume the usual sized ones.
The pressures at on-off are important. The clutch should turn off at about 22, on again at about 40.
What's really important now is the vent temp. It should be between 55 and 60. If it's higher than 60 your system is contaminated with air and water.
That's why you are supposed to pump them down to vacuum of 29 inHg if they lost all refrigerant.
The key element here is: When you do this routine, do you have to add 134 before the compressor will run? If you do it has air in it.
As far as how much refrigerant to add, there's a label on the radiator/fan cover or thereabouts that show capacity. That is how much to add to an empty system. Never add more than that.. it can handle MAYBE 6 oz extra but that's pushing it.
Newer AC systems have gotten pretty robust and can handle some abuse but I'm thinking yours is living on borrowed time.. When that compressor grenades you will have to replace the condensor and clean and flush the lines and evap, at the least.
The oil. Do you mean the standard size cans with 134a + oil. Or the smaller one that just is oil with a refrigerant charge {it says to hold upside down I think}. Also slow leaks rarely lose much oil so I'm pretty sure you have too much oil in it. I would suggest you change your accumulator next time.
And by 134 cans I assume the usual sized ones.
The pressures at on-off are important. The clutch should turn off at about 22, on again at about 40.
What's really important now is the vent temp. It should be between 55 and 60. If it's higher than 60 your system is contaminated with air and water.
That's why you are supposed to pump them down to vacuum of 29 inHg if they lost all refrigerant.
The key element here is: When you do this routine, do you have to add 134 before the compressor will run? If you do it has air in it.
As far as how much refrigerant to add, there's a label on the radiator/fan cover or thereabouts that show capacity. That is how much to add to an empty system. Never add more than that.. it can handle MAYBE 6 oz extra but that's pushing it.
Newer AC systems have gotten pretty robust and can handle some abuse but I'm thinking yours is living on borrowed time.. When that compressor grenades you will have to replace the condensor and clean and flush the lines and evap, at the least.
Last edited by pettyfog; 03-19-2012 at 07:26 AM.
#4
03-19-2012, 02:55 PM
Join Date: Jan 2009
Location: Eastern Central New York State
Posts: 1,003
Your descriptions are too vague..
The oil. Do you mean the standard size cans with 134a + oil. Or the smaller one that just is oil with a refrigerant charge {it says to hold upside down I think}. Also slow leaks rarely lose much oil so I'm pretty sure you have too much oil in it. I would suggest you change your accumulator next time.
And by 134 cans I assume the usual sized ones.
The pressures at on-off are important. The clutch should turn off at about 22, on again at about 40.
What's really important now is the vent temp. It should be between 55 and 60. If it's higher than 60 your system is contaminated with air and water.
That's why you are supposed to pump them down to vacuum of 29 inHg if they lost all refrigerant.
The key element here is: When you do this routine, do you have to add 134 before the compressor will run? If you do it has air in it.
As far as how much refrigerant to add, there's a label on the radiator/fan cover or thereabouts that show capacity. That is how much to add to an empty system. Never add more than that.. it can handle MAYBE 6 oz extra but that's pushing it.
Newer AC systems have gotten pretty robust and can handle some abuse but I'm thinking yours is living on borrowed time.. When that compressor grenades you will have to replace the condensor and clean and flush the lines and evap, at the least.
The oil. Do you mean the standard size cans with 134a + oil. Or the smaller one that just is oil with a refrigerant charge {it says to hold upside down I think}. Also slow leaks rarely lose much oil so I'm pretty sure you have too much oil in it. I would suggest you change your accumulator next time.
And by 134 cans I assume the usual sized ones.
The pressures at on-off are important. The clutch should turn off at about 22, on again at about 40.
What's really important now is the vent temp. It should be between 55 and 60. If it's higher than 60 your system is contaminated with air and water.
That's why you are supposed to pump them down to vacuum of 29 inHg if they lost all refrigerant.
The key element here is: When you do this routine, do you have to add 134 before the compressor will run? If you do it has air in it.
As far as how much refrigerant to add, there's a label on the radiator/fan cover or thereabouts that show capacity. That is how much to add to an empty system. Never add more than that.. it can handle MAYBE 6 oz extra but that's pushing it.
Newer AC systems have gotten pretty robust and can handle some abuse but I'm thinking yours is living on borrowed time.. When that compressor grenades you will have to replace the condensor and clean and flush the lines and evap, at the least.
When the charge was lower, it would turn on and off at the appropriate times, but now it holds steady in the correct range for the temperature with the compressor steady on at idle. The thermometer said it was around 70 and it was around 32PSI on the low side. Those pressures are with the A/C on full. When I turn it off and the compressor unlocks, it goes up to 75 and stops, which is at the upper limit of the gauge.
I used an IR thermometer and it was between 52 and 58 pointing it at the dash vent.
When I charged it originally, it wasn't totally discharged. It had maybe 10-20 PSI in it, but the compressor was not cycling on so it was low to be of any use for A/C.
How is mine living on borrowed time exactly? Just because of mileage or something else? I added that oil to keep the compressor from seizing and it is running pretty quietly. Just curious.
The A/C is working. The only real problem is that it has a slow leak, but even with the UV dye I put in 3 years ago that is still in the system I can't find anything.
Thanks
EDIT: Also, I looked around with a blacklight and didn't find any obvious leaks, but I am finding tiny traces of dye (as in little faint dots) around the compressor area. But nothing to point to the site of a leak unfortunately.
Last edited by ComputerNerdBD; 03-19-2012 at 08:01 PM.
#5
03-19-2012, 09:59 PM
VERY common for the H6 compressor to develop a "belly leak", usually on the bottom where the case halves come together. When, not if, that happens, it's time for a new compressor. Too much or too little oil and or refrigerant will destroy the system. Best to have a competent, certified A/C technician with the proper training and equipment do the job.
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