A/C questions
Thread Starter
Joined: Dec 2004
Posts: 1,294
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From: Dallas (Richardson), TX, USA
A/C questions Sorry if this is in the wrong thread, but I'm not sure where else to put it. It's also on the wrong site as this is for my beater, but you guys rule, so someone probably knows the answers to my questions.
My Explorer's A/C has been out for a couple of years. The system appears to have no pressure in it, so I'm assuming that I need to fix a leak before refilling it. I've seen those cans of the UV leak finding refrigerant, and I've got a few questions:
1) If I put a single can of the UV stuff in there, would that cause enough pressure for me to be able to find leaks?
2) Can the UV stuff actually be used as refrigerant, or does it all need to be removed and then replaced with regular R-134a?
3) I've seen the pressurized cans of UV refrigerant, but there's also regular bottles of UV "lubricant." Where in the world do you put that stuff?
Any help would be greatly appreciated. The Texas heat is killing me on the way home every day because I can't get my 2/50 AC (2 windows down, 50mph) to work in stop-and-go traffic.
My Explorer's A/C has been out for a couple of years. The system appears to have no pressure in it, so I'm assuming that I need to fix a leak before refilling it. I've seen those cans of the UV leak finding refrigerant, and I've got a few questions:
1) If I put a single can of the UV stuff in there, would that cause enough pressure for me to be able to find leaks?
2) Can the UV stuff actually be used as refrigerant, or does it all need to be removed and then replaced with regular R-134a?
3) I've seen the pressurized cans of UV refrigerant, but there's also regular bottles of UV "lubricant." Where in the world do you put that stuff?
Any help would be greatly appreciated. The Texas heat is killing me on the way home every day because I can't get my 2/50 AC (2 windows down, 50mph) to work in stop-and-go traffic.
1) Not positive but I think you need some R134 as well, but it may also depend on the leak detect kit. I looked into this the other day and can't seem to remember, just call O'reilly's and ask, they were actually very knowledgable when I did my a/c.
2) No, after you find and repair the leak you will need to evacuate the system before recharging
3) After you determine where the leak is, go back to the store to buy the new parts. They have a book that will tell you how many ounces of R134 you need to buy and how many ounces and what type of oil you need to buy. I recommend you use an a/c gauge manifold to install the R134/oil. You should be able to buy one at the parts store, but you can probably get one at Harbor freight for less.
AW
2) No, after you find and repair the leak you will need to evacuate the system before recharging
3) After you determine where the leak is, go back to the store to buy the new parts. They have a book that will tell you how many ounces of R134 you need to buy and how many ounces and what type of oil you need to buy. I recommend you use an a/c gauge manifold to install the R134/oil. You should be able to buy one at the parts store, but you can probably get one at Harbor freight for less.
AW
Thread Starter
Joined: Dec 2004
Posts: 1,294
Likes: 0
From: Dallas (Richardson), TX, USA
I have rented an a/c gauge manifold already to check the pressure in the system. The oil gets injected into the system the same way as the refrigerant itself?
Thanks for the reply, btw!
Thanks for the reply, btw!
Not to rain on your parade but if it has been out for a couple of years the chances of getting it back up and running smoothly is rather thin. The refridgerant contains oils and conditioners that keep the parts and seals in shape, and without them and no use for a couple years things are probably toast.
Just an fyi if you are on a tight budget. Even if you do find an obvious leak, there's a very high chance it won't hold or will have other problems. I'd hate to see someone spend a bunch of time and a couple hundred bucks just to find this out.
The Jiffy Lube I used to work at (many years ago) would do free pressure testing on A/C systems. If your compressor actually still kicks on and cycles, then I would try taking it to one of those places and make them do the legwork. We (that place) would also take some liability for the recharge - being that if we found the system pressure was good - there was a warranty on the recharge. If something else went wrong or the freon leaked out from somewhere we missed, the customer could get a refund.
Not sure what it's like nowadays, just how it was back then. We had plenty of customers that would pay for a recharge knowing the system would only hold it for a month or so.
Just an fyi if you are on a tight budget. Even if you do find an obvious leak, there's a very high chance it won't hold or will have other problems. I'd hate to see someone spend a bunch of time and a couple hundred bucks just to find this out.
The Jiffy Lube I used to work at (many years ago) would do free pressure testing on A/C systems. If your compressor actually still kicks on and cycles, then I would try taking it to one of those places and make them do the legwork. We (that place) would also take some liability for the recharge - being that if we found the system pressure was good - there was a warranty on the recharge. If something else went wrong or the freon leaked out from somewhere we missed, the customer could get a refund.
Not sure what it's like nowadays, just how it was back then. We had plenty of customers that would pay for a recharge knowing the system would only hold it for a month or so.
there should be a label under the hood of your car that says how much refrigerant the system uses and how much oil. The system has high and low pressure switches so you have to make sure you charge the system with the correct amount or your pressures will not be in spec. and the a/c wont work even with a "over" full charge.
As for the leak finding stuff, UV oil is leak detector and refrigerant oil mixed. Make sure you use the right type of oil for your system. R134a and R12 use different oils and are not compatible at all. One uses PAG and one uses Mineral oil. I dont remember which is which at the moment (brain fart, I really should know this).
I dont know what type of things they sell at wal-mart, oreillys, napa, etc to recharge the a/c system (i work at a dealership so i use the a/c machine) but you do need pressure in the system (meaning refrigerant and oil) for the leak detector to work. It has to be cycled through the whole system so it shows every possible leak. It does suck because you pay for the refrigerant your going to lose soon anyways, just to fix a leak and recharge again.
BUT - a lot of car manufacturers put dye in the system at the factory so you might be lucky and already have it in there. just grab a black light and do some searching.
As for the leak finding stuff, UV oil is leak detector and refrigerant oil mixed. Make sure you use the right type of oil for your system. R134a and R12 use different oils and are not compatible at all. One uses PAG and one uses Mineral oil. I dont remember which is which at the moment (brain fart, I really should know this).
I dont know what type of things they sell at wal-mart, oreillys, napa, etc to recharge the a/c system (i work at a dealership so i use the a/c machine) but you do need pressure in the system (meaning refrigerant and oil) for the leak detector to work. It has to be cycled through the whole system so it shows every possible leak. It does suck because you pay for the refrigerant your going to lose soon anyways, just to fix a leak and recharge again.
BUT - a lot of car manufacturers put dye in the system at the factory so you might be lucky and already have it in there. just grab a black light and do some searching.
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if you have access to compressed air, you can buy an adapter and coupler to pressurize the system with plain old air, and then spray really soapy water all over every component and see where the leaks are coming from...let the air out, fix, then recheck...then let the air out,you'll need to evacuate (pull the system into a vacuum with a vacuum pump) add some oil and 134a...see if the system works. after sitting that long, most likely will need an accumulator, which also has a dessicant in it to absorb moisture
might just be easier to take it to a shop to give you an estimate on whats wrong..and then fix it yourself
might just be easier to take it to a shop to give you an estimate on whats wrong..and then fix it yourself
Thread Starter
Joined: Dec 2004
Posts: 1,294
Likes: 0
From: Dallas (Richardson), TX, USA
As pathetic as this may sound, I don't see where the oil goes. I'm digging through a Haynes manual, but they only mention the refrigerant. I assume the oil has to go somewhere in the compressor?
I bought a $7 A/C repair video at AutoZone last week, and watched it, so I'm now an expert. 
In the video, the guy added oil by pouring it in 2 places... 4 ozs to the accumulator/dryer, and 4 ozs directly in the compressor, then spinning the compressor by hand about a dozen times to mix it in... this was with a new off the shelf compressor. An old one will still have some oil in it.
If your parts are already together, you have 2 options. One would be to purchase a special can of refrigerant with oil already mixed together, or if your system is discharged, you can buy just a little bottle of oil and remove the schrader valve stem from the line inlet, and pour it in. The 134a systems take PAG oil, and GM's take (I believe!) the ISO 150 variety. Ford is different.
Normal cans of refrigerant do not have oil in them.
As for the leak detector, if your system is discharged, you can remove a schrader valve and pour the little vial in, and then put 1 can of refrigerant in there and cycle the system, and look for leaks with the UV light and glasses. A leak detector kit (with the dye, light, and glasses) is about $40.
I'm about to buy all this stuff for my own repairs. I only have 1 car (my truck) with A/C that works right now. Need to fix that.
In the video, the guy added oil by pouring it in 2 places... 4 ozs to the accumulator/dryer, and 4 ozs directly in the compressor, then spinning the compressor by hand about a dozen times to mix it in... this was with a new off the shelf compressor. An old one will still have some oil in it.
If your parts are already together, you have 2 options. One would be to purchase a special can of refrigerant with oil already mixed together, or if your system is discharged, you can buy just a little bottle of oil and remove the schrader valve stem from the line inlet, and pour it in. The 134a systems take PAG oil, and GM's take (I believe!) the ISO 150 variety. Ford is different.
Normal cans of refrigerant do not have oil in them.
As for the leak detector, if your system is discharged, you can remove a schrader valve and pour the little vial in, and then put 1 can of refrigerant in there and cycle the system, and look for leaks with the UV light and glasses. A leak detector kit (with the dye, light, and glasses) is about $40.
I'm about to buy all this stuff for my own repairs. I only have 1 car (my truck) with A/C that works right now. Need to fix that.
Last edited by Camaroholic; Jun 26, 2006 at 11:31 AM.
