Posted: 8/8/2026 2:47:44 AM EDT
[Last Edit: Amish_Bill][Edited]
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I've got two cars with empty AC systems that will be needing new condensers. One via accident, one via age. If I replace the condenser/dryer, and pull a vacuum to dry it out and check for leaks, does this also remove the old compressor oil? I'd imagine it would boil off just like other moisture, but I have been wrong once or twice. If it doesn't boil it off, any rules of thumb about how much to assume is still here and how much to add back in? Cars in question - 07 Towncar, 02 Suburban 2500 LT |
Disclaimer - OP is bad at knowing things, and might catch on fire.
Vet - Op MMAMA
Every other species kills off their stupid......we cater to them. -- spin-drift
Nobody ever called 911&said I just did something smart. -- TheFlynDutchman
Vet - Op MMAMA
Every other species kills off their stupid......we cater to them. -- spin-drift
Nobody ever called 911&said I just did something smart. -- TheFlynDutchman
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Pulling a vacuum does not remove any oil, only atmosphere and moisture. If you want to start with a fresh oil charge, blow out the old system using nitrogen to remove the oil. |
What is a democrat? Someone who wants everything you have, except for your job.
Politicians should wear uniforms like NASCAR drivers so we could see their corporate sponsors.
Politicians should wear uniforms like NASCAR drivers so we could see their corporate sponsors.
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OK - followup question. My Eagle Eye Vision (tm) has detected that all the top Amazon listings for refrigerant are labelled "143a 'replacement'"... Is this normal or am I seeing the cheapest 'almost kinda exactly the same but not quite' substitutes? If I'm just going to be putting random crap in, why not go fully cheap and use propane? Attached File   Failed To Load Product Data |
Disclaimer - OP is bad at knowing things, and might catch on fire.
Vet - Op MMAMA
Every other species kills off their stupid......we cater to them. -- spin-drift
Nobody ever called 911&said I just did something smart. -- TheFlynDutchman
Vet - Op MMAMA
Every other species kills off their stupid......we cater to them. -- spin-drift
Nobody ever called 911&said I just did something smart. -- TheFlynDutchman
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And, while I'm asking, is a cheaper 1 stage vac pump enough for the task, or is a slightly more expensive 2 stage far superior / required? ... seems 2 stage is preferred for understandable reasons, so I'm guessing 1 stage would be the "I care enough to almost do it right but still wind up wasting my money" option. Looks like this one is the better cheapskate shadetree option: Failed To Load Product Data .... then this seems to say that 1 stage will be simpler and cheaper for light duty work like car AC.... https://hvacolink.com/single-stage-vs-two-stage-vacuum-pumps/ |
Disclaimer - OP is bad at knowing things, and might catch on fire.
Vet - Op MMAMA
Every other species kills off their stupid......we cater to them. -- spin-drift
Nobody ever called 911&said I just did something smart. -- TheFlynDutchman
Vet - Op MMAMA
Every other species kills off their stupid......we cater to them. -- spin-drift
Nobody ever called 911&said I just did something smart. -- TheFlynDutchman
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Originally Posted By Aggie_Gunner: The oil in AC systems typically doesn't even start to degrade until about 400oF. It won't turn to vapor with a vacuum pulled on it. I've got the first condenser and some dye ordered, and it looks like Real 134a at Harbor Freight might be the most convenient answer. Now, the only real outstanding acquisition question is, cheap 1 stage pump or cheap 2 stage pump. I doubt it will see use on a car even a half dozen times in my lifetime, so pro durability is not a need. Hmmm... Craigslist & FBMP? |
Disclaimer - OP is bad at knowing things, and might catch on fire.
Vet - Op MMAMA
Every other species kills off their stupid......we cater to them. -- spin-drift
Nobody ever called 911&said I just did something smart. -- TheFlynDutchman
Vet - Op MMAMA
Every other species kills off their stupid......we cater to them. -- spin-drift
Nobody ever called 911&said I just did something smart. -- TheFlynDutchman
|
Originally Posted By Amish_Bill: I've seen this answer enough that I'm comofortable with it. I've got the first condenser and some dye ordered, and it looks like Real 134a at Harbor Freight might be the most convenient answer. Now, the only real outstanding acquisition question is, cheap 1 stage pump or cheap 2 stage pump. I doubt it will see use on a car even a half dozen times in my lifetime, so pro durability is not a need. Hmmm... Craigslist & FBMP? One car has been charged for over 20 years now. |
Preferred pronoun: MARINE
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I've been using a single-stage vacuum pump for years on automotive a/c systems, and it works fine. Draw it down to 30 inches, and let it sit an hour or so. If the vacuum is still good, dump in the first can as a liquid(turn it upside down), and then top it off with gas(leave the can upright). Stick a thermometer in one of the vents and look for at least a low temp of 50 degrees, depending on the ambient temp. |
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Get a micron gauge. Don’t pull to 30” and call it good. Thats not the proper way to pull a vacuum. |
What is a democrat? Someone who wants everything you have, except for your job.
Politicians should wear uniforms like NASCAR drivers so we could see their corporate sponsors.
Politicians should wear uniforms like NASCAR drivers so we could see their corporate sponsors.
|
Originally Posted By Amish_Bill: OK - followup question. My Eagle Eye Vision (tm) has detected that all the top Amazon listings for refrigerant are labelled "143a 'replacement'"... Is this normal or am I seeing the cheapest 'almost kinda exactly the same but not quite' substitutes? If I'm just going to be putting random crap in, why not go fully cheap and use propane? https://www.ar15.com/media/mediaFiles/1410/134a_replacement_PNG-3809513.JPGwww.amazon.com/dp/B0DF36J51S With states like mine banning the sale of 134a, Amazon just found it easier to stop selling it altogether. Do not use the "replacement" stuff. |
"You can't tourniquet a taint, folks." - Andrew Branca
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Originally Posted By belted_guns: Why? Is replacement another word for previously used, reclaimed refrigerant? Originally Posted By belted_guns: Originally Posted By JackRebney: With states like mine banning the sale of 134a, Amazon just found it easier to stop selling it altogether. Do not use the "replacement" stuff. Why? Is replacement another word for previously used, reclaimed refrigerant? I would much rather use reclaimed 134a. "Replacement" is a mixture of R-290 and R-600a. More common names for those refrigerants are Propane and Isobutane. |
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1: ES is, as mentioned above, propane, and I don't think it's compatible with PAG oil. 2: If the system was open, the PAG in it is probably wet/ruined. 3: Believe it or not, a compressor is a 'minor replaced component' when it comes to replacing the quantity of oil that was removed with the old component. Condensers are among the major components. You will have to add oil when you replace a condenser. But...how much oil??? 4: I'd be tempted to flush the system with something, and/or remove and drain the compressor to get the bad PAG out. Then refill with the 'full system replacement' quantity of PAG, and replace the receiver/dryer if it's not built into the condenser. |
Exposure to views that distress and offend is a form of education unto itself. -U.S. Court of Appeals for the Ninth Circuit in Reges v Cauce
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Originally Posted By PepePewPew: 1: ES is, as mentioned above, propane, and I don't think it's compatible with PAG oil. 2: If the system was open, the PAG in it is probably wet/ruined. 3: Believe it or not, a compressor is a 'minor replaced component' when it comes to replacing the quantity of oil that was removed with the old component. Condensers are among the major components. You will have to add oil when you replace a condenser. But...how much oil??? 4: I'd be tempted to flush the system with something, and/or remove and drain the compressor to get the bad PAG out. Then refill with the 'full system replacement' quantity of PAG, and replace the receiver/dryer if it's not built into the condenser. Is there an easy layman method to know if a condenser has the dryer built in? |
Disclaimer - OP is bad at knowing things, and might catch on fire.
Vet - Op MMAMA
Every other species kills off their stupid......we cater to them. -- spin-drift
Nobody ever called 911&said I just did something smart. -- TheFlynDutchman
Vet - Op MMAMA
Every other species kills off their stupid......we cater to them. -- spin-drift
Nobody ever called 911&said I just did something smart. -- TheFlynDutchman
| the drier is a can shaped device , its either attached to the condensor or near it along the line from comp to condensor.And yes you need it, add oil the the system per manual. you can tilt the condensor on edge to drain it to see how much oil is there a starting point |
Dobro is watching you, and you dont even know it
when arfcom cares enough to let GD be searchable, ill care about dupes
when arfcom cares enough to let GD be searchable, ill care about dupes
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Originally Posted By Amish_Bill: The system is empty, but it was a leak, not an open line. Is there an easy layman method to know if a condenser has the dryer built in? Originally Posted By Amish_Bill: Originally Posted By PepePewPew: 1: ES is, as mentioned above, propane, and I don't think it's compatible with PAG oil. 2: If the system was open, the PAG in it is probably wet/ruined. 3: Believe it or not, a compressor is a 'minor replaced component' when it comes to replacing the quantity of oil that was removed with the old component. Condensers are among the major components. You will have to add oil when you replace a condenser. But...how much oil??? 4: I'd be tempted to flush the system with something, and/or remove and drain the compressor to get the bad PAG out. Then refill with the 'full system replacement' quantity of PAG, and replace the receiver/dryer if it's not built into the condenser. Is there an easy layman method to know if a condenser has the dryer built in? Follow the line coming out of the condenser, the receiver/drier will be in that line. It's a cylinder full of desiccant,if it's built in it will generally be tall and thin and welded to the side of the condenser. Otherwise, it will be mounted nearby, typically a shorter/thicker cylinder. |
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Originally Posted By ZW17: Get a micron gauge. Don’t pull to 30” and call it good. Thats not the proper way to pull a vacuum. Virtually no one who works on automotive AC units uses micron gauges. Nothing wrong with using one if you want to but virtually no one does. So, yes, pulling a 30” vacuum on an automotive system IS correct. |
"It behooves every man to remember that the work of the critic is of altogether secondary importance, and that, in the end, progress is accomplished by the man who does things."
Theodore Roosevelt
Theodore Roosevelt
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Originally Posted By JackRebney: With states like mine banning the sale of 134a, Amazon just found it easier to stop selling it altogether. Do not use the "replacement" stuff. Guess next time you are in a state that you can buy it at, stock up! |
"It behooves every man to remember that the work of the critic is of altogether secondary importance, and that, in the end, progress is accomplished by the man who does things."
Theodore Roosevelt
Theodore Roosevelt
|
Originally Posted By PepePewPew: 1: ES is, as mentioned above, propane, and I don't think it's compatible with PAG oil. 2: If the system was open, the PAG in it is probably wet/ruined. 3: Believe it or not, a compressor is a 'minor replaced component' when it comes to replacing the quantity of oil that was removed with the old component. Condensers are among the major components. You will have to add oil when you replace a condenser. But...how much oil??? 4: I'd be tempted to flush the system with something, and/or remove and drain the compressor to get the bad PAG out. Then refill with the 'full system replacement' quantity of PAG, and replace the receiver/dryer if it's not built into the condenser. Opening a system to replace a component will not hurt anything and will not necessitate the need to replace the oil. An empty system that has slowly leaked out over time will not have moisture in it either. The only time an oil replacement is an issue is if the system has been actually open (like a disconnected line) for a lengthy amount of time. If you have to open a system and leave it open, then cap the lines and it’ll still be fine when it’s time to reconnect everything. If the compressor has failed, you do want to flush the lines to remove any contaminants the compressor might have sent into the lines/evaporator/condenser etc. If the OP wants to do overkill, go right ahead. But he’s wasting money and time. But it’s his money and time so it’s up to him. |
"It behooves every man to remember that the work of the critic is of altogether secondary importance, and that, in the end, progress is accomplished by the man who does things."
Theodore Roosevelt
Theodore Roosevelt
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Originally Posted By Amish_Bill: The system is empty, but it was a leak, not an open line. Is there an easy layman method to know if a condenser has the dryer built in? You’ll have to look it up. But as long as your system has been closed, a leak won’t cause issues with moisture in the dryer. Most common place to find a slow leak is the schrader valves. I found a leaking evaporator in my Jeep TJ when I bought it. Ended up replacing the evaporator and the condenser. Also replaced the dryer because it was cheap and easy and I didn’t know the history of past repairs. Replaced the schrader valves for good measure, the orifice, and all orings on any part I removed. Pulled a vacuum to 30 inches (no micron gauge) and then charged it. Ran it for several years with no AC issues running ice cold the entire time until I sold it earlier this year. |
"It behooves every man to remember that the work of the critic is of altogether secondary importance, and that, in the end, progress is accomplished by the man who does things."
Theodore Roosevelt
Theodore Roosevelt
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Originally Posted By ColtRifle: Guess next time you are in a state that you can buy it at, stock up! Originally Posted By ColtRifle: Originally Posted By JackRebney: With states like mine banning the sale of 134a, Amazon just found it easier to stop selling it altogether. Do not use the "replacement" stuff. Guess next time you are in a state that you can buy it at, stock up! I bought a case on eBay as soon as I heard about the ban. |
"You can't tourniquet a taint, folks." - Andrew Branca
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Originally Posted By JackRebney: I bought a case on eBay as soon as I heard about the ban. Smart. I stocked up just to have it even though my state has no restrictions on it. I have a bunch of 12 oz cans I paid $10 for. They have gone up to about $13 per can. Of course, still MUCH cheaper than $50 per can for R1234YF |
"It behooves every man to remember that the work of the critic is of altogether secondary importance, and that, in the end, progress is accomplished by the man who does things."
Theodore Roosevelt
Theodore Roosevelt
|
This is from the Enviro-Safe website; "Is Enviro-Safe™ Refrigerant compatible with all refrigerant oils? Yes, Enviro-Safe™ is totally compatible with all refrigerant oil available today. It can be used with Mineral, Ester and PAG oils without incompatibility." |
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Epstein Scalia did not kill himself.
Gun control is literally Hitler.
Trump's actions? Watergate does not bother me, does your conscience bother you?
Gun control is literally Hitler.
Trump's actions? Watergate does not bother me, does your conscience bother you?
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When the AC first went out a few years ago, I had a commercial auto AC shop check it out. They're the ones that diagnosed a slow condenser leak and topped it off. The next few years I added some 134 at the beginning of the summer. The time between needing a charge has steadily dropped, and now it's FO time on a repair. I'm going to guess that the shop would have replaced my valves as a matter of Best Practice. Off to shop for a cheap pump... |
Disclaimer - OP is bad at knowing things, and might catch on fire.
Vet - Op MMAMA
Every other species kills off their stupid......we cater to them. -- spin-drift
Nobody ever called 911&said I just did something smart. -- TheFlynDutchman
Vet - Op MMAMA
Every other species kills off their stupid......we cater to them. -- spin-drift
Nobody ever called 911&said I just did something smart. -- TheFlynDutchman
|
I've been happy with the inexpensive Harbor Freight vacuum pump for the handful of times I've needed it for AC repairs. If anything, the quality of their stuff has gone in the 15 or so years since I bought it, too. You might check your local Autozone or O'Reily to see if they have a vacuum pump on their loan-a-tool program. |
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Originally Posted By Amish_Bill: When the AC first went out a few years ago, I had a commercial auto AC shop check it out. They're the ones that diagnosed a slow condenser leak and topped it off. The next few years I added some 134 at the beginning of the summer. The time between needing a charge has steadily dropped, and now it's FO time on a repair. I'm going to guess that the shop would have replaced my valves as a matter of Best Practice. Off to shop for a cheap pump... Condensers are usually easy to replace. Evaporators….not so much! |
"It behooves every man to remember that the work of the critic is of altogether secondary importance, and that, in the end, progress is accomplished by the man who does things."
Theodore Roosevelt
Theodore Roosevelt
|
Originally Posted By wlderdude: I've been happy with the inexpensive Harbor Freight vacuum pump for the handful of times I've needed it for AC repairs. If anything, the quality of their stuff has gone in the 15 or so years since I bought it, too. You might check your local Autozone or O'Reily to see if they have a vacuum pump on their loan-a-tool program. I’ve also seen them cheap on Facebook marketplace. |
"It behooves every man to remember that the work of the critic is of altogether secondary importance, and that, in the end, progress is accomplished by the man who does things."
Theodore Roosevelt
Theodore Roosevelt
|
Originally Posted By ColtRifle: Virtually no one who works on automotive AC units uses micron gauges. Nothing wrong with using one if you want to but virtually no one does. So, yes, pulling a 30” vacuum on an automotive system IS correct. Originally Posted By ColtRifle: Originally Posted By ZW17: Get a micron gauge. Don’t pull to 30” and call it good. Thats not the proper way to pull a vacuum. Virtually no one who works on automotive AC units uses micron gauges. Nothing wrong with using one if you want to but virtually no one does. So, yes, pulling a 30” vacuum on an automotive system IS correct. Every modern AC REcovery machine with an automatic vac made uses a micron gauge/sensor to know when vac processes is completed. This will typically take about 7-8 minutes to vac with our machines. Saves a lot of time vs vac it for 20-30 minutes to make sure moisture is out because you don’t know and want to be safe. |
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Originally Posted By Quicky06: Every modern AC REcovery machine with an automatic vac made uses a micron gauge/sensor to know when vac processes is completed. This will typically take about 7-8 minutes to vac with our machines. Saves a lot of time vs vac it for 20-30 minutes to make sure moisture is out because you don’t know and want to be safe. Every mechanic I know who uses an actual machine for AC work doesn’t use a machine with a micron gauge. I have no doubt they exist but, at least where I am, they don’t appear to be common. I’m guessing a lot of independent shops in my area are using older machines (quite likely) but I’ve never asked them how old their machines are. I imagine the over priced dealers mechanic shops use the latest and greatest machines for everything….probably one of many reasons why they are overpriced! Bottom line…it’s not needed. If you have it….sure use it. But, mechanics (professional and DIY) have been charging automotive AC systems without a micron gauge for many years with zero issues. |
"It behooves every man to remember that the work of the critic is of altogether secondary importance, and that, in the end, progress is accomplished by the man who does things."
Theodore Roosevelt
Theodore Roosevelt
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Originally Posted By ColtRifle: Every mechanic I know who uses an actual machine for AC work doesn’t use a machine with a micron gauge. I have no doubt they exist but, at least where I am, they don’t appear to be common. I’m guessing a lot of independent shops in my area are using older machines (quite likely) but I’ve never asked them how old their machines are. I imagine the over priced dealers mechanic shops use the latest and greatest machines for everything….probably one of many reasons why they are overpriced! Bottom line…it’s not needed. If you have it….sure use it. But, mechanics (professional and DIY) have been charging automotive AC systems without a micron gauge for many years with zero issues. I’d like to know how you quantify “zero issues”? Are you able to determine that a compressor with a less than perfect vacuum and moisture in the system should last 10yrs or maybe with a perfect vacuum it would last 15yrs? Thats an impossible statement. Look, best practices are that all the moisture and atmosphere be removed leaving only pure refrigerant in the system, I think we can all agree with that. 30”hg will never determine a perfect vacuum, 100 microns will. 30”hg and a 1hr standing test will not show micro cracks or moisture in a system, a micron gauge will. Use best practices. A micron gauge is the best way to make a refrigeration repair. Moisture is public enemy #1 with refrigerants, it will greatly reduce the life of a system. You have to get rid of all of it. |
What is a democrat? Someone who wants everything you have, except for your job.
Politicians should wear uniforms like NASCAR drivers so we could see their corporate sponsors.
Politicians should wear uniforms like NASCAR drivers so we could see their corporate sponsors.
|
Originally Posted By ZW17: ... Use best practices. A micron gauge is the best way to make a refrigeration repair. Moisture is public enemy #1 with refrigerants, it will greatly reduce the life of a system. You have to get rid of all of it. I am saying the entire system is already 19 years old. This can easily be seen as a low dollar patch to help the system survive till the rest of the car fails. |
Disclaimer - OP is bad at knowing things, and might catch on fire.
Vet - Op MMAMA
Every other species kills off their stupid......we cater to them. -- spin-drift
Nobody ever called 911&said I just did something smart. -- TheFlynDutchman
Vet - Op MMAMA
Every other species kills off their stupid......we cater to them. -- spin-drift
Nobody ever called 911&said I just did something smart. -- TheFlynDutchman