Always appreciate CZcamsrs that share their knowledge and skill. It was also refreshing to see that you corrected yourself in the comment section that vacuuming an a/c system does not remove oil. Just want to make three points for newbies that may attempt this: 1. When connecting & disconnecting both quick connect couplers to the Low & High side ports, they should be in the Closed (counterclock wise position) meaning the needle is in the retracted position. Then make sure your gauges are in the closed position. And then Open the quick connect couplers by turning them clockwise to depress the needle. 2. Your system had no refrigerant to begin with. That indicates that you like replaced a component such as the compressor before starting this procedure. In that case, vacuuming the system is the logical next step. However for most others who are simply attempting to add refrigerant to a system that is low on refrigerant, you will not be vacuuming the system UNLESS you have evacuated the system first. This is the preferred method but requires an evacuation procedure and likely a service station to perform that function (likely at $0 to minimal cost since they benefit from the recaptured refrigerant). 3. You should not need to re-bleed your yellow line between can-change charges if you temporarily close the valves at the can and manifold during the changeover before resuming the process. Thanks for the video!
Thanks for watching & for the instruction! A/C can suck! but if you can get it to work following this process, if everything is in good working order, it will save you a ton of money!
Well I did get the ac compressor changed and the ac recharged working great you still helped a lot ....but being my first time it came out great but won't be the last thanks...
I went into heat stroke and woke up in ICU because I couldn't recharge my truck's ac system. I had a temp of 107°. This video will be very helpful. Thank you. M
pag oil does not evaporate under vaccum - only when exposed to air (positive pressure) most cars have 7 ounces total in the system. the 2oz cans should be added from time to time and its a really easy and cheap way to do it. DO NOT ADD 7 ounces when charging a system. Even if you buy and replace the compressor DO NOT ADD A FULL 7 ounces. The compressor will come with 3 ounces already - you do not want to overfill the system with PAG oil.
Thanks for the needed info Will. I find that if I quickly release Freon pressure (via schraeder valve) from a possible overcharge that the pag oil spurts out on the hood of car and engine, but if I depress the valve slightly there is much less liquid oil coming out, mostly vapor.
Thanks for the clarification! I was wrong in saying the oil gets drawn out or evaporates when the system is vacuumed. While you may lose some oil when the refrigerant is removed from the system, you won't lose it all and drawing a vacuum won't remove any more. Correct, most compressors do come prefilled with oil, so keep that in mind when doing a replacement.
[*This is to viewers who may attempt to connect a manifold gauge set to a system and try to charge it.] Although he is initially pulling a vacuum, essentially removing any/all non-condensables from the system, the proper way to perform the initial steps would have been to first turn the vacuum pump on before back-seating (opening) the valves on the gauges. Other non-condensables (and possibly other refrigerant types from previous use) most likely exist inside of the hoses, and could travel into the system. It's always good practice to get into that habit in case you ever forget to purge your hoses one day. Also, you never want to pull a vacuum on a system that has a leak. [If your A/C system doesn't have any refrigerant in it, or is otherwise low according to its factory sticker or nameplate, IT HAS A LEAK. These systems are closed systems (meaning the refrigerant never gets 'used up' or is depleted from a system. It should still maintain its factory charge, whatever amount was weighed in after it was manufactured.)] The first step on a system that is suspected of having a leak is to first find that leak using an electronic leak detector in conjunction with a soap bubble solution. If the system is completely empty, pressurize it to the system's minimal, allowable low-side pressure with nitrogen, with a trace amount of the refrigerant that belongs in that system. A side note: A digital manifold gauge set (such as the Fieldpiece SMAN) works great, and is very accurate when monitoring your inches of mercury (i.e., your vacuum pressures). It facilitates decay tests, vacuum pressure tests, etc. You need to test your hoses individually, to verify they aren't leaking at their fittings through the O-rings, etc. Otherwise, you may be chasing a leak in a system that doesn't exist. When using an analog gauge set while pulling a vacuum, its impossible to know where your vacuum is at during the decay test; you can't see with accuracy how far down into a vacuum you are pulling the system. Am analog gauge set doesn't display microns - the crucial measurement used to help facilitate pulling a refrigeration system down into a deep vacuum. [The EPA (Environmental Protection Agency) recommends that we are to pull a minimal, single, deep vacuum of 500 microns, or a triple-vacuum of 1000 microns.] This is where a digital manifold or a micron gauge comes in handy. If, during the decay test, the system creeps up past 1000 microns withing a 20-minute span, there is still a leak in the system, and will need to be addressed before continuing.
@@blackericdenice I may just take you up on that offer! At the moment, I am extremely busy juggling school, work, and studying for my Contractor's License and 2nd NATE Certification. I promise you a video when we take our break for our 3rd semester, which will be in about two or three more weeks! I just subscribed to your channel, by the way; Nice to meet you! 🤗
Hi HVAC Parabellum X, can you please recommend a digital manifold gauge that's not too expensive for DIY purposes? The one you recommended above (Fieldpiece SMAN) is $800.
"Back-seating" is not the same as "opening". The valves at the guages are front-seat only type valves, where full CW closes the valve and CCW opens the valve, just like a valve for a garden hose. The old refrigerant can taps that pierced the can had both front seat and back seat positions, meaning no refrigerant flow in the full CW (front seat) or full CCW (backseat) position. The back-seat position allowed you to remove the empty can and screw on the new can without piercing the new can.
Always turn the valves off before installing them on to the vehicle's ports. If you install them fully open two things can happen. First if the valve is open you can damage the vehicle's port (needle) Second refrigerant can escape and may cause air to enter the system
Good advice! Especially important if you are just adding coolant to an already charged system, but even if you know the system is empty it would be good practice to start with the valves closed out of the box.
Love the detail on this video. You went step by step in explaining everything instead of assuming someones knowledge and skipping over what would be "common knowledge"
I’m a new in your channel and for sure you are a good teacher explaining step by step how to complete a a/c charge, thank you very much you video is very helpful
Thanks for your support! You're too kind. Not the best at explaining things at times, but luckily there's a comment section to get help from everyone! haha
Glad I stumbled onto your video. I have watched another mechanic (he's a lot more animated) for years and he's really good too. I will come back to you often as my ancient vehicles (4 from 2014) need help. Well done and thanks. I subscribed today
Splendid video Ole Chap. A most brilliant, simple, yet thorough explanation of the Do's and Dont's. I am naming my next offspring after you my good man. Cherio!
Good rule of thumb is high side should be twice ambient air temp in degrees F. Wondering, could you use engine vacuum to suck the system down if you didnt have a vacuum pump?
Dont ever pull your refrigerant from the high pressure side. And dont ever recharge to the high pressure side. Thats is a VAPOR line. You're wanting to pull LIQUID ONLY! The low pressure hookup is a liquid line. Please be e609 certified before servicing AC systems.
Great Video! I actually bought the same pump and guage setup and watched to refresh my brain before vacuuming. Good thing as I forgot to open the red/high side. doh! I hit a deer at 70mph and totalled my truck. I rebuilt it including AC condenser and dryer. Final touches. Driving home tonight at dark it was blowing 39F out of the vent. I had to turn it off. I credit using a scale that measures grams and put in just about exactly the factory stated 875 grams for my old Dodge. It's COLD! Awesome!
Awesome! Glad it helped. I reference the steps and videos every time I go to do something. Awesome idea to use a scale to make sure everything is accurate before it goes in.
Good video Im going to do mine kust got the stuff to,does the oil come in the freon or is it seperate?suggestion, try not to shake the can makes it hard to read.
Thanks for watching! And great suggestion. The oil and Freon are separate, unless you buy the quick charge cans with it combined. However, unless you’ve done a repair to where a new compressor doesn’t come prefilled you do not need to add any oil. The video is incorrect in stating pulling a vacuum removes the oil, it does not.
How do you know how much oil was in the system? You can’t just throw 2 ozs of oil into a system! Your compressor has oil in it, unless you replaced it! Plus your sondrnsor has oil in it, so just because you were low on Freon, has nothing to do with how much oil is in system, unless you have replaced parts! Putting to much oil is as bad as no oil! 42 years mechanic here and telling people bad information will cause damage!
I like your video, but I think you made one mistake. You said when you vacuum it takes the oil out. Not true.😌. The oil does not boil by vacuum pressure only water and moisture. The oil does stay inside of it. If you think I’m wrong please send me proof so I can stop blowing up cars 😅
Don't know who told you that .Unless you are changeing a compressor then you would need to put the correct amount of pag or ester oil you are only takeing mosture out your system not oil do not ad oil.
If we have an oil injector, should you inject the oil after you recharge or before? Because wouldn't that mess up your vacuum? And if after, would it be okay? the compressor wont get messed up without oil?
Great question! I was incorrect in stating oil is removed when vacuuming. It is Not. You should add any oil before running the vacuum as it would be easiest. Most compressors come pre-oiled so take that into account when adding.
Some videos connect the yell9w hose to the top valve on 5he vac pump, while yours connects to the side valve on the pump...please explain the difference between the two. Thank you
Thanks for watching! I'm not a certified mechanic and not sure... revving the engine really shouldn't change the rate at which the compressor is spinning, not sure what could cause the drop or how the pressures should behave. What's important is the pressure with the system running when checking / refilling it - always done this at idle A/C on and never had problems unless there's a leak or something.
If I install the new AC. Compressor and there is an oil in it , if I do a vacuum the ac system, is there a possibility that the oil in Ac compressor will drain out during vacuuming operation?
No. You do not need to add additional oil. The video is incorrect in saying pulling a vacuum removes the oil, it does not. I could see adding a little to the compressor depending on how much oil it comes prefilled with vs. the system requirement. All of which I would do before installation.
You can get a UV light and glasses to see if you can see it - most refrigerants have UV dye added or you can add it to the system. Or they make sniffers, cheap tools that detect the refrigerant. Then you just slowly wave or crawl this along all the A/C system and see what it picks up.
Nice Video! If I want to hook up the AC manifold to your car to do some measurements for the pressure, should I purge the blue and read lines from air once I connect them or no need as the air will not get into the system? please clarify thx
Thanks for watching! I don't believe you need to purge lines to just to check pressures, no air should get into the system when checking. Not a certified mechanic so be sure to verify this with the manifold's manual.
How did you evac the oil and freon? Where is it going? Does the vacuum pump have a resorvoir and holding tank? If not then how are you removing it from the system
Great question and thanks for watching! To evacuate the Freon, say before a repair, you must take the car to a mechanic to have it removed and “recycled.” Opening the system up to the environment is harmful and illegal. You only ever need to pull a vacuum on the A/C system to refill it, if it is already totally empty and has been open to air.
Great question! Pulling a vacuum does Not remove oil from the system. I misspoke in the video. The best way would be prefill with oil, then vacuum, and then add the refrigerant. Most new compressors come prefilled with 3-5oz of oil, so start from there.
@@EYVOAuto you should edit your video and remove references to adding oil and put something in the comments about oil because people will not read all the comments.
What do you do with the valve at on the yellow line at the gauge???? Does it need to be open or closed for suction, filling? No where does anyone mention this valve?
Yes, it's to purge air from the lines after you connect a can, but before you let it begin filling the system. Once you get some freon to come out, shut it, then open the valve to the system to begin filling.
I have a question on the pag oil. It looks like some refrigerants come with pag oil in them, do I need to add the straight oil on top of this if I use that kind of refrigerant or should these have enough oil to be ok?
Great question. I was incorrect to say pulling a vacuum removes the oil. It does not. With that said, you should be fine with the Freon that contains oil. But, unless you’ve done a major repair where the component was not prefilled with oil, I wouldn’t worry about adding much.
Thanks for the video, I'm done an LS engine swap & purchased a nice aftermarket sadon compressor, they let you know it comes with oil in it, I'm wondering why it does, if you have to vacuum pump it before charging and it removes the oil?
Thanks for watching! That is an exact question I have! My new compressor for our Camry came "pre-oiled" but a mechanic buddy told me to be sure I add more oil to the system anyways - supposedly pulling a vacuum does remove some of the oil. I'm guessing it doesn't remove all of it, but who knows? I've also wondered if the compressor has lubricated parts that aren't where the freon runs through? Great question! Does anyone know? - drop a comment
@@EYVOAuto When you open the system, my limited understanding is that you should always replace the dryer as well. I dumped my dryer oil out into a Solo cup and it was roughly a shot and a half (about 1.5 ounces). I added oil into my new dryer to match and so far it is working great. The discarded oil looked a little "rode hard and put up wet."
@@packrat9433 Yes I’ve heard that as well. Probably would be a good idea just to keep things in tip top shape & start fresh with no moisture in the system. I’ve been lucky with no problems, but this would be a good practice
I know this was a year ago , but if you buy a new compressor , your supposed to dump the oil out before you install it and measure it , you look up your vehicle manual for correct pag oil , and unless you know what's in that new compressor I usually throw that out and start fresh with the recommended pag oil , but out of curiosity I always measure it , and I will add exactly that amount , each component will hold some oil , after you get it charged correctly , it will let you know if it's low on oil , I hired a shop to do my wife's truck and they skipped the pag oil part , it rattles bad when it kicks on , there second attempt , same results ..I guess I gotta do it ..I even supplied the bottle of pag oil ..they probably just kept it and didn't put any in neither time ..still rattles hard ..
@@MikeSmith-nu9wt I hate that you don't realize that even with all that, you did a hole Lotta stating the Obvious but didn't Answer the question... From a year ago. Hang in there.
Great question! Shut the gauges at the manifold, the ports, and then disconnect the ports. The schrader valves will keep the ports closed off to the outside once the hoses are disconnected.
@@EYVOAuto thank you. Let me see if i understand, i got the shut the gauges at the manifold part but for the ports, are you referring to the coupler valves that are connected to the low and high side ports? Shut them off and then disconnect them only or disconnect them and manifold ports? Hmm i think i have the shrader valves setup differently where those ends are on the gauge ports since thats how the picture was showing in the manual haha. Think i got the setup incorrect but not sure if it matters
loosen the fitting just enough that the air in the line escapes. As soon as you notice freon tighten it back up. This is how I have to do mine. Been tempted to buy some new gauges that will have that feature.
Agreed with @gregmorris6604. Some people don't bother to bleed the line and say their A/C works just fine. I say why give it the chance for anything to go wrong? You really don't want any air in the system so its worth the extra trouble and precaution just to be safe...
Thank you for the video. I have cheap gauges from Amazon and someone had commented to snug up the connections with pliers because of the cheap seals in the fittings. 6 mos later, second time around, I forgot and leaked my Freon. Do you think I lost any oil?
Wow, great advice, I'll have to check mine! I'm not 100% sure. Probably Lost a little, but unless you're changing a component you shouldn't lose all the oil. I also misspoke in the video, pulling a vacuum will not remove the oil. It might be a good idea to add a little, but not the full recommended amount. You might do a little more research or ask a mechanic just to be sure as well. Thanks for watching!
@@EYVOAuto Thank you for the quick reply. Even after snugging the connections with pliers, the cheap seals only slightly compress and then you can loosen very easily by hand. My system takes 7oz of pag 46 oil. If I add a "little", do you think 1oz is enough? Too much? Thx again.
Honestly if it were me I would probably add one PAG quick charge can. I think they contain 2oz of oil and a little freon. But again I'm not a certified mechanic so might be worth asking one just to verify
If the valves are closed like you say to do at 6:12, why would the gauges ever change? The lines are closed off from the system so how would it ever lose pressure? I cant wrap my head around this, please advise. Every video I have seen says to do it this way. My car doesnt leak by doing the method everyone says, but once I put freon in, it leaks out within 2 days. The vacuum test, done the way everyone shows doesnt show me that it has a leak. And I believe it is because the gauges are closed and it will never identify if there is a leak.
Great question! None of the valves open or close the pressure gauges directly, they're just part of the manifold and read the manifold pressure on the low & high side. The valves on the manifold only shut off the center yellow line from the valve side. If they are shut and the hoses are connected, with the hose-end valve open, the gauges will read the system pressure since that is what the manifold is sealed off to. Make sure you're leaving the hoses open and just shutting the valves on the manifold for the test. The valves on the manifold only shut off/open any in/out flow from the outside world. The valves on the hose-ends open/close the hoses. The gauges always read the pressure of the manifold and aren't turned off or on by the valves. Sounds like you may have a very slow leak that might not be detected by just a 45min pressure test. I'm not a certified mechanic but you might try adding some UV dye to the system and see if you can find the leak using a light. The high side is under a lot of pressure so it could be leaking out there more easily when running.
@@EYVOAuto It sounds like his leak is the Shrader valve namely the A/C System Valve Core. Here is the part from Autozone: Santech / A/C System Valve Core Part Number: MT0064-4. And make sure the Valve Core has the caps on. The caps are marked H high side and L for lowside. A/C System Valve Core and Cap Kit Part Number: MT29 . You can use a different brand if you want.
Hey Man I’m not getting any vacuum I opened the gauges and left it running for about 45 mins and still at 0 turned it off to see if I’m still getting a vacuum and nothing please help brotha I live in az and it’s hot
What if I'm just topping off my freon, how do I know how much refrigerant I need to buy ? Is the vacuum process necessary? Any advice appreciated, Troy
Nope, no freon left in the system. Only reason to pull a vacuum is when the system is completely empty and has been opened to the environment, such as after a repair. It's to evacuate all the air so you can pull freon into a completely empty system. To remove freon before opening the system, like to do a repair, you'll need to take the car to a shop to have it evacuated and collected.
Newer vehicles are using r1234yf freon very expensive but taking it to a shop for recharge is 600$ also scotty kilmer says you dont have to hook up to the high side only the low side to evacuate the system & as for adding oil most of the freon already has oil in it.
Freon with oil in it and/or stop leak is roughly twice as expensive. I refilled an empy system for 3 small cans of R134a at $11 a peice from Orielly's. PAG oil was $9.99 and I have half of it left and half a can of freon left as well. Roughly $50 total. IF you don't need the extras don't dump them in your system. Keep it clean and mean. I'm still running good on my 2001 compressor. The condenser met a deer and neither of them speak anymore.
Man r123yf is ridiculous. I hate the day when I purchase a car with that stupid gas in the system. Also the little cans for just regular r134 are pretty price, so buying one with a little bit of oil in it just shoots up the price. I always add oil separately and look for cans that are pure gas and no other additives.
@@packrat9433 I noticed this as well when recharging my system. Hurt a little bit spending $12 on a 3oz can of freon +2oz oil... but in the end it was still cheaper than taking it to a shop!
All car ac systems are OPEN systems, they are not completely truly sealed as they have rubber O rings that will shrink and dry over time releasing gas gradually. This is normal, pulling a vacuum on a system that has lost its R134a gas is superfluous. Vacuum the system, and add new R134A gas to spec. If the system is normal that will do it, if not then you have bigger issues.
Yes, you will need to take the car in to a mechanic to have the Freon removed properly before replacing the compressor. Then you will need a vacuum in order to refill the system after the compressor replacement.
You pulled a vacuum on system and then verified no leaks. How do you know how much R134 and oil are present in the system before you begin adding R134 and oil? What am I missing?
If you have to pull a vacuum, there is no refrigerant left in the system. You have to pull a vacuum when it is empty in order to remove the air and refill it. There is a sticker under the hood telling you how much refrigerant & oil the system requires.
Actually, you're right! Did a little bit more research and while the vacuum may remove the moisture it does not evaporate the oil. What removes the oil is when you have a leak in the system over a period of time or if you replace a major component. Best idea is to add a tiny amount when adding freon to replace anything the system has used, but no need to refill the entire amount upon a recharge unless you replaced a major component and it's not prefilled.
Hi, I'm confused as I've read some of the comments here and seems this procedure(performing a vacuum in system) is only done when a new component(new compressor) was replaced. My vehicle doesn't have cold air and whould like to add r-134u with a UV dye in it, to check for a leak. Should I vaccum the system? Thanks for the video*
While adding refrigerant, what would cause the psi on the high pressure gauge to go really high (400-500)? The high pressure side was closed the whole time while adding refrigerant.
Great question! There is a little schrader valve in between the blue & red valve handles, under the viewing glass. You'll remove the stem cap & push it in until refrigerant comes out. Once bled you can open up the port & let the refrigerant flow in air-free.
Vacuum pump DOESN’T get rid of oil! Shouldn’t effect oil charge at all, unless you replaced parts! Never add oil because you Freon was low! Never! That’s why when you replace compressors or condensor, you measure the oil you drain out of components!
You must open both gauges when running the vacuum so it will pull a vacuum on both sides. If you don't open one, it will not draw a vacuum on that side & there will be air in the system when you go to refill it. Refilling it is when you shut the high side and use the low side only with the A/C compressor running. That will move the freon from the low side to the high and begin to pressure everything up.
Great question! I'd get oil in there and then the Freon since there's a lot of moving parts in the system that need lubricated. If you use oil charge cans you can get some of both at the same time!
Great question. I used a few PAG quick charge cans that were 2oz of oil and 1 or 2oz? of refrigerant. It's necessary if you change the compressor and it doesn't come pre-oiled. I misspoke when I said vacuuming the system removes the oil, it does not. But doesn't hurt to make sure it's topped off either
@@EYVOAuto Thank you for your reply. I've a question, I am replacing the rear expansion valve and O-rings bcuz I found my AC this summer blowing warm. Upon inspecting the right rear shock on my 2015 Town and Country, I discovered green liquid dripping from that expansion valve/Evap junction. I pulled it apart yesterday and sure enough, the aluminum ring with center rubber O-rings were deteriorated, thereby causing the leak. The evaporator is in great shape, and the expansion valve looks ok but I am going to replace that. Now I imagine this must have been leaking some oil all winter. So I have purchased everything you have shown on this video, manifold gauges/hoses, vacuum pump, 2 new Schrader valves (bcuz I did see bubbles at the low port valve), three cans of 12oz R134a and an 8oz bottle of pag 46 oil. Bare in mind my van has front and rear AC. It takes 1150g / (2.53 lb) of freon, but at this point, I don't know how much pag 46 oil to add. So my question here is, being that this system was leaking gas and oil, How much oil should I add? I'm thinking, 3 or 4oz..? What say ye? Thx.
I all I want to do is check the pressure in the system can you tell me which ports to have open or closed. Do I start off with all ports closed, run the engine and AC for 5 minutes, then open all ports to check the pressure or just open the high and low at the ports and leave the ports at the gauges closed or open all ports to check the pressure?
You'll have to draw a vacuum on the system 1st which means you'll have to add oil with the freon when you recharge it. If the system is still charged, just low, you can add just freon through a quick recharge can.
And there was a study book you can send for ,the questions at the end of the book , if you can answer them without looking it back up in the book , you will pass too . I still got mine ..the places I used to work for payed for all my certifications , but I've been out of the field a while now ..brushing up the memory a little ..
I know when you buy the AC pump it does come pre-charged with roughly 3 oz of oil in it I know you can add the oil too the pump itself but after you start to charge the r134a do you still need to put the oil in after so much refrigerant
Great question! I was mistaken in saying to add oil to the system. You'll only want to add oil if the compressor you replaced was not pre-filled or had less than the car's recommended amount. Drawing a vacuum does not pull the oil out. If you need to you can add oil at anytime with an oil injector or you can add it with a quick-charge can when refilling.
Why would you add oil to the system if you did not replace the compressor and even then the oil is added to the compressor it self which usually comes prefilled
Thanks for watching! I misspoke in the video, you'll only want to add oil if you're replacing the compressor and the new one did not come prefilled. A leak will also cause some of the oil to leak out, but not necessarily the whole amount. However, I was incorrect to say the vacuum will remove the oil, it evaporates moisture not oil.
Okay, so I messed up in the video by saying you need to add oil. If your compressor did not come pre-filled you will need to add. If it did, you are good the vacuuming will not remove the oil. Now a high pressure refrigerant leak will remove a lot, so if you just replaced lines due to that, add. Talking to my mechanic buddies it's a good practice to add a little anyways to just top it off, again if you didn't change a major component or it didn't come pre-filled.
Are there different sized values that is used on the Freon recharge can which the yellow recharge line connect to? I bought a Freon recharge can and a valve for the can to connect to my yellow recharge line but the yellow recharge line connector does not screw on.
Thanks for watching! That I am not sure about, it seems like all the quick charge cans I have ever used have been the same size. I know some are self-sealing and others are the puncture-type cans. It you're using a puncture-type can, they make an adapter you can screw onto your yellow line or quick-recharge valve and then into that can that will break the seal - only problem with those is you cannot unscrew the can until it is empty since they do not seal back up.
I am trying to do it on my car following your video but I ran into a problem that the vacuum is not going below -26. Is that enough? It does hold vacuum for 45min like you said but I’m a bit worried. What should I do?
Totally agree with the comments. You want to draw a vacuum and you want it to hold for some time before charging, just to verify there are no leaks. Could be an inaccurate reading on the gauge or could be that's all the pump will give. Either way you should be fine for the recharge as long as it holds -pressure.
@@EYVOAuto Thanks for the reply guys. I ended up postponing the project after getting a new pump and manifold line. And followed your instructions properly. Later while I tried to recharge the ac and connected Freon can...it only sucked in a tiny bit at the beginning and then stopped taking in any freon at all. Treid it multiple time with multiple ways without yielding any result. It feels like there is an obstacle that is not letting the gas go in. So next summer I'll probably replace the entire A/C system on my car.
You can add it that way if it is in a quick-charge can. In liquid form, with a charged system, you'll have to use an oil injector. I misspoke when I say drawing a vacuum will remove oil, it does not. If your compressor / major component replacement comes prefilled you should be pretty close to the correct level. Now, if you had a large leak (broken hose / evacuated it quickly, etc.), this will remove some of the oil. Where I did no mechanical work to my A/C system & had a leak, I topped it off with oil just to be safe. Still working great!
Thanks for watching! While I’m not a certified mechanic, It’s probably best to stick with the refrigerant specified for your system to ensure proper operation.
Hi great question and thanks for watching! To top off a low, non-leaking, system you may want to just use a quick recharge can / system and follow it's instructions. That'd probably be the easiest. Now for refilling an empty system, there should be a sticker under the hood telling you how much refrigerant to use, oil, and some pressure guidelines which vary slightly depending on the temperature outside...
Here is the link to the exact kit I used. It is a 4 CFM. If you don't want to buy one, you can "rent" one from O'reilly's / Advanced Auto Parts that will work great as well. I'm not sure what size theirs is.
1.8 cfm should work; it would just take longer, maybe an hour of suction instead of 30 minutes, but the 4 cfm is safer, quicker, and better, and you can probably borrow one from your auto parts place.
I have been doing DIY work on my cars for two to three years and have not seen a definitive method of finding out how much oil you have left. There is charts that tell you how much to add after replacing parts, but thats about it.
Some say you can dump the compressor out and measure it then add accordingly. But most new components will note how much oil they are prefilled with. Pulling a vacuum does Not remove any of the oil.
Hi, thanks for watching again! You'll have to add the oil after vacuuming the system, when you go to charge it again. You can either use actual oil and an oil injector or you can use an oil charge can mixed with a little bit of Freon. The oil charge cans are the easiest, but also the most expensive - they are different from the Freon cans. You car should say on it or in the manual how much Freon and oil it takes - make sure you put that amount in for it to work properly for a long time.
Hello and thanks so much for your videos, they're very helpful. Have a question though; after vacuuming the system and verified that there's no leaks, i connected the can of refrigerant and nothing happened, seems that the can is not puncture good or something like that because I have no flow of refrigerant whenever I tried purging the air out at the end of the yellow hose on the manifold. Any ideas??
Yes, I just recently did, I saw a video where they're using a different tool to puncture the can on the side, it really helped me. The only diwn side is that you can't use the can partially, once is punctured, and once you take the tool off the can, if there's refrigerant left in the can, it goes to waste.
Always appreciate CZcamsrs that share their knowledge and skill. It was also refreshing to see that you corrected yourself in the comment section that vacuuming an a/c system does not remove oil. Just want to make three points for newbies that may attempt this:
1. When connecting & disconnecting both quick connect couplers to the Low & High side ports, they should be in the Closed (counterclock wise position) meaning the needle is in the retracted position. Then make sure your gauges are in the closed position. And then Open the quick connect couplers by turning them clockwise to depress the needle.
2. Your system had no refrigerant to begin with. That indicates that you like replaced a component such as the compressor before starting this procedure. In that case, vacuuming the system is the logical next step. However for most others who are simply attempting to add refrigerant to a system that is low on refrigerant, you will not be vacuuming the system UNLESS you have evacuated the system first. This is the preferred method but requires an evacuation procedure and likely a service station to perform that function (likely at $0 to minimal cost since they benefit from the recaptured refrigerant).
3. You should not need to re-bleed your yellow line between can-change charges if you temporarily close the valves at the can and manifold during the changeover before resuming the process.
Thanks for the video!
Thanks for watching & for the instruction! A/C can suck! but if you can get it to work following this process, if everything is in good working order, it will save you a ton of money!
Well I did get the ac compressor changed and the ac recharged working great you still helped a lot ....but being my first time it came out great but won't be the last thanks...
I went into heat stroke and woke up in ICU because I couldn't recharge my truck's ac system. I had a temp of 107°.
This video will be very helpful.
Thank you.
M
That's exactly the answer I was looking for thanks for the advice!!!!
@@MMorMM Thanks for watching! Get it fixed man!!!
pag oil does not evaporate under vaccum - only when exposed to air (positive pressure) most cars have 7 ounces total in the system. the 2oz cans should be added from time to time and its a really easy and cheap way to do it. DO NOT ADD 7 ounces when charging a system. Even if you buy and replace the compressor DO NOT ADD A FULL 7 ounces. The compressor will come with 3 ounces already - you do not want to overfill the system with PAG oil.
ABSOLUTELY CORRECT!
Thanks for the needed info Will. I find that if I quickly release Freon pressure (via schraeder valve) from a possible overcharge that the pag oil spurts out on the hood of car and engine, but if I depress the valve slightly there is much less liquid oil coming out, mostly vapor.
Thanks for the clarification! I was wrong in saying the oil gets drawn out or evaporates when the system is vacuumed. While you may lose some oil when the refrigerant is removed from the system, you won't lose it all and drawing a vacuum won't remove any more. Correct, most compressors do come prefilled with oil, so keep that in mind when doing a replacement.
Please I had a leak exploded the ac line ,I have to add more oil ?
Came here to say this. I typically only charge .5oz of pag
[*This is to viewers who may attempt to connect a manifold gauge set to a system and try to charge it.]
Although he is initially pulling a vacuum, essentially removing any/all non-condensables from the system, the proper way to perform the initial steps would have been to first turn the vacuum pump on before back-seating (opening) the valves on the gauges. Other non-condensables (and possibly other refrigerant types from previous use) most likely exist inside of the hoses, and could travel into the system. It's always good practice to get into that habit in case you ever forget to purge your hoses one day.
Also, you never want to pull a vacuum on a system that has a leak. [If your A/C system doesn't have any refrigerant in it, or is otherwise low according to its factory sticker or nameplate, IT HAS A LEAK. These systems are closed systems (meaning the refrigerant never gets 'used up' or is depleted from a system. It should still maintain its factory charge, whatever amount was weighed in after it was manufactured.)] The first step on a system that is suspected of having a leak is to first find that leak using an electronic leak detector in conjunction with a soap bubble solution. If the system is completely empty, pressurize it to the system's minimal, allowable low-side pressure with nitrogen, with a trace amount of the refrigerant that belongs in that system.
A side note: A digital manifold gauge set (such as the Fieldpiece SMAN) works great, and is very accurate when monitoring your inches of mercury (i.e., your vacuum pressures). It facilitates decay tests, vacuum pressure tests, etc.
You need to test your hoses individually, to verify they aren't leaking at their fittings through the O-rings, etc. Otherwise, you may be chasing a leak in a system that doesn't exist.
When using an analog gauge set while pulling a vacuum, its impossible to know where your vacuum is at during the decay test; you can't see with accuracy how far down into a vacuum you are pulling the system. Am analog gauge set doesn't display microns - the crucial measurement used to help facilitate pulling a refrigeration system down into a deep vacuum. [The EPA (Environmental Protection Agency) recommends that we are to pull a minimal, single, deep vacuum of 500 microns, or a triple-vacuum of 1000 microns.] This is where a digital manifold or a micron gauge comes in handy.
If, during the decay test, the system creeps up past 1000 microns withing a 20-minute span, there is still a leak in the system, and will need to be addressed before continuing.
Why don’t you upload a video with all this information you have?
@@blackericdenice I may just take you up on that offer!
At the moment, I am extremely busy juggling school, work, and studying for my Contractor's License and 2nd NATE Certification.
I promise you a video when we take our break for our 3rd semester, which will be in about two or three more weeks!
I just subscribed to your channel, by the way; Nice to meet you! 🤗
@@ParabellumX Cool and thank you
Hi HVAC Parabellum X, can you please recommend a digital manifold gauge that's not too expensive for DIY purposes? The one you recommended above (Fieldpiece SMAN) is $800.
"Back-seating" is not the same as "opening". The valves at the guages are front-seat only type valves, where full CW closes the valve and CCW opens the valve, just like a valve for a garden hose. The old refrigerant can taps that pierced the can had both front seat and back seat positions, meaning no refrigerant flow in the full CW (front seat) or full CCW (backseat) position. The back-seat position allowed you to remove the empty can and screw on the new can without piercing the new can.
Always turn the valves off before installing them on to the vehicle's ports. If you install them fully open two things can happen.
First if the valve is open you can damage the vehicle's port (needle)
Second refrigerant can escape and may cause air to enter the system
Good advice! Especially important if you are just adding coolant to an already charged system, but even if you know the system is empty it would be good practice to start with the valves closed out of the box.
@@EYVOAuto No coolant in an A/C system, it's refrigerant
@@zeke112964 haha, thanks for the clarification
Love the detail on this video. You went step by step in explaining everything instead of assuming someones knowledge and skipping over what would be "common knowledge"
Thanks for watching! Glad it helped out!
I’m a new in your channel and for sure you are a good teacher explaining step by step how to complete a a/c charge, thank you very much you video is very helpful
Thanks for your support! You're too kind. Not the best at explaining things at times, but luckily there's a comment section to get help from everyone! haha
Dude 🎉 this guy for the win- saved me so much money- very good job explaining everything
Thanks so much for watching! Glad it helped out
Thanks so much for watching! Glad it helped out
2 Years late : NO OIL TO BE ADDED : Vacuuming a system does NOT remove oil. Oil is only added to a new compressor (if) it does not come pre oiled!
Thanks for the clarification. Exactly right!
… and if you replace the condenser, don’t you have to add something like 1/3 oz?
Glad I stumbled onto your video. I have watched another mechanic (he's a lot more animated) for years and he's really good too. I will come back to you often as my ancient vehicles (4 from 2014) need help. Well done and thanks. I subscribed today
Thanks for watching and the support!
Very good video in detail, thank you for helping others how to fix the ac
Thanks for the support!
The best video on this I've found. Simply an excellent explanation. Thanks for sharing.
Thanks for watching! Glad it was helpful!
Splendid video Ole Chap. A most brilliant, simple, yet thorough explanation of the Do's and Dont's. I am naming my next offspring after you my good man. Cherio!
Thanks for watching!
Good rule of thumb is high side should be twice ambient air temp in degrees F. Wondering, could you use engine vacuum to suck the system down if you didnt have a vacuum pump?
Dont ever pull your refrigerant from the high pressure side. And dont ever recharge to the high pressure side. Thats is a VAPOR line. You're wanting to pull LIQUID ONLY! The low pressure hookup is a liquid line. Please be e609 certified before servicing AC systems.
Great Video! I actually bought the same pump and guage setup and watched to refresh my brain before vacuuming. Good thing as I forgot to open the red/high side. doh!
I hit a deer at 70mph and totalled my truck. I rebuilt it including AC condenser and dryer. Final touches. Driving home tonight at dark it was blowing 39F out of the vent. I had to turn it off.
I credit using a scale that measures grams and put in just about exactly the factory stated 875 grams for my old Dodge. It's COLD! Awesome!
Awesome! Glad it helped. I reference the steps and videos every time I go to do something. Awesome idea to use a scale to make sure everything is accurate before it goes in.
Good video Im going to do mine kust got the stuff to,does the oil come in the freon or is it seperate?suggestion, try not to shake the can makes it hard to read.
Thanks for watching! And great suggestion. The oil and Freon are separate, unless you buy the quick charge cans with it combined.
However, unless you’ve done a repair to where a new compressor doesn’t come prefilled you do not need to add any oil. The video is incorrect in stating pulling a vacuum removes the oil, it does not.
Thank you so much for making this video.
Thanks for watching!
How do you know how much oil was in the system? You can’t just throw 2 ozs of oil into a system! Your compressor has oil in it, unless you replaced it! Plus your sondrnsor has oil in it, so just because you were low on Freon, has nothing to do with how much oil is in system, unless you have replaced parts! Putting to much oil is as bad as no oil! 42 years mechanic here and telling people bad information will cause damage!
Tremendous help thank you for the video. Unfortunately my chevy has 1234yf. I'll have to buy those fittings since 1234a fitting doesn't work
Your presentation on your tutorial was awesome 👍💯
Thanks for watching, your comment is awesome!
You very welcome 🤙
I like your video, but I think you made one mistake. You said when you vacuum it takes the oil out. Not true.😌. The oil does not boil by vacuum pressure only water and moisture. The oil does stay inside of it. If you think I’m wrong please send me proof so I can stop blowing up cars 😅
Correct! Pulling a vacuum does Not remove oil from the system. I need to clip that part of the video out. Good catch! Thanks for watching
Don't know who told you that .Unless you are changeing a compressor then you would need to put the correct amount of pag or ester oil you are only takeing mosture out your system not oil do not ad oil.
Correct! Pulling a vacuum does Not remove oil from the system.
If we have an oil injector, should you inject the oil after you recharge or before? Because wouldn't that mess up your vacuum? And if after, would it be okay? the compressor wont get messed up without oil?
Great question! I was incorrect in stating oil is removed when vacuuming. It is Not. You should add any oil before running the vacuum as it would be easiest. Most compressors come pre-oiled so take that into account when adding.
Some videos connect the yell9w hose to the top valve on 5he vac pump, while yours connects to the side valve on the pump...please explain the difference between the two. Thank you
One is a different size than the other. Depends on your hose.
Should the low pressure gauge of near 40 psi drop when you accelerate the vehicle’s engine?
Thanks for watching! I'm not a certified mechanic and not sure... revving the engine really shouldn't change the rate at which the compressor is spinning, not sure what could cause the drop or how the pressures should behave. What's important is the pressure with the system running when checking / refilling it - always done this at idle A/C on and never had problems unless there's a leak or something.
If I install the new AC. Compressor and there is an oil in it , if I do a vacuum the ac system, is there a possibility that the oil in Ac compressor will drain out during vacuuming operation?
No. You do not need to add additional oil. The video is incorrect in saying pulling a vacuum removes the oil, it does not.
I could see adding a little to the compressor depending on how much oil it comes prefilled with vs. the system requirement. All of which I would do before installation.
Wow ! You have zero dislikes - that's a great explanation and all I need to know to do the job myself, thank you ....🙂
Thanks for watching! Made a few mistakes in the video, but between it and the comments hope it helped!
Thanks a lot for your information. I want to know how we can find a leak in a system
They sell a cheap tool online that listens for the sound of leaking air and you put it near all the possible leaking spot
You can get a UV light and glasses to see if you can see it - most refrigerants have UV dye added or you can add it to the system.
Or they make sniffers, cheap tools that detect the refrigerant. Then you just slowly wave or crawl this along all the A/C system and see what it picks up.
Nice Video! If I want to hook up the AC manifold to your car to do some measurements for the pressure, should I purge the blue and read lines from air once I connect them or no need as the air will not get into the system? please clarify thx
Thanks for watching! I don't believe you need to purge lines to just to check pressures, no air should get into the system when checking. Not a certified mechanic so be sure to verify this with the manifold's manual.
How did you evac the oil and freon? Where is it going? Does the vacuum pump have a resorvoir and holding tank? If not then how are you removing it from the system
Great question and thanks for watching! To evacuate the Freon, say before a repair, you must take the car to a mechanic to have it removed and “recycled.” Opening the system up to the environment is harmful and illegal.
You only ever need to pull a vacuum on the A/C system to refill it, if it is already totally empty and has been open to air.
Should you put the oil in first if changing the compressor and then the Freon or vice versa?
Great question! Pulling a vacuum does Not remove oil from the system. I misspoke in the video. The best way would be prefill with oil, then vacuum, and then add the refrigerant. Most new compressors come prefilled with 3-5oz of oil, so start from there.
@@EYVOAuto you should edit your video and remove references to adding oil and put something in the comments about oil because people will not read all the comments.
What do you do with the valve at on the yellow line at the gauge???? Does it need to be open or closed for suction, filling? No where does anyone mention this valve?
It’s for before you add the Freon to purge the air from the line
Yes, it's to purge air from the lines after you connect a can, but before you let it begin filling the system. Once you get some freon to come out, shut it, then open the valve to the system to begin filling.
I have a question on the pag oil. It looks like some refrigerants come with pag oil in them, do I need to add the straight oil on top of this if I use that kind of refrigerant or should these have enough oil to be ok?
Great question. I was incorrect to say pulling a vacuum removes the oil. It does not. With that said, you should be fine with the Freon that contains oil. But, unless you’ve done a major repair where the component was not prefilled with oil, I wouldn’t worry about adding much.
Thanks for the video, I'm done an LS engine swap & purchased a nice aftermarket sadon compressor, they let you know it comes with oil in it, I'm wondering why it does, if you have to vacuum pump it before charging and it removes the oil?
Thanks for watching! That is an exact question I have! My new compressor for our Camry came "pre-oiled" but a mechanic buddy told me to be sure I add more oil to the system anyways - supposedly pulling a vacuum does remove some of the oil. I'm guessing it doesn't remove all of it, but who knows? I've also wondered if the compressor has lubricated parts that aren't where the freon runs through? Great question! Does anyone know? - drop a comment
@@EYVOAuto When you open the system, my limited understanding is that you should always replace the dryer as well. I dumped my dryer oil out into a Solo cup and it was roughly a shot and a half (about 1.5 ounces). I added oil into my new dryer to match and so far it is working great. The discarded oil looked a little "rode hard and put up wet."
@@packrat9433 Yes I’ve heard that as well. Probably would be a good idea just to keep things in tip top shape & start fresh with no moisture in the system. I’ve been lucky with no problems, but this would be a good practice
I know this was a year ago , but if you buy a new compressor , your supposed to dump the oil out before you install it and measure it , you look up your vehicle manual for correct pag oil , and unless you know what's in that new compressor I usually throw that out and start fresh with the recommended pag oil , but out of curiosity I always measure it , and I will add exactly that amount , each component will hold some oil , after you get it charged correctly , it will let you know if it's low on oil , I hired a shop to do my wife's truck and they skipped the pag oil part , it rattles bad when it kicks on , there second attempt , same results ..I guess I gotta do it ..I even supplied the bottle of pag oil ..they probably just kept it and didn't put any in neither time ..still rattles hard ..
@@MikeSmith-nu9wt I hate that you don't realize that even with all that, you did a hole Lotta stating the Obvious but didn't Answer the question... From a year ago. Hang in there.
Wait wait, when did the oil canister get hooked up to the yellow line?? Confused here
great video, what is the best way to disconnect everything when charging or adding freon back is done?
Great question! Shut the gauges at the manifold, the ports, and then disconnect the ports. The schrader valves will keep the ports closed off to the outside once the hoses are disconnected.
@@EYVOAuto thank you. Let me see if i understand, i got the shut the gauges at the manifold part but for the ports, are you referring to the coupler valves that are connected to the low and high side ports? Shut them off and then disconnect them only or disconnect them and manifold ports? Hmm i think i have the shrader valves setup differently where those ends are on the gauge ports since thats how the picture was showing in the manual haha. Think i got the setup incorrect but not sure if it matters
What if my gauges don’t have a shrader valve in the middle line to purge the air before adding refriderabt?
loosen the fitting just enough that the air in the line escapes. As soon as you notice freon tighten it back up. This is how I have to do mine. Been tempted to buy some new gauges that will have that feature.
Agreed with @gregmorris6604. Some people don't bother to bleed the line and say their A/C works just fine. I say why give it the chance for anything to go wrong? You really don't want any air in the system so its worth the extra trouble and precaution just to be safe...
When doing a recharge with a manifold set- is it okay to keep the high-pressure house connected with the Gage knob closed and the service part open?
Yes, at 9:05 he said to do that to monitor the pressure as it's filling.
Yes, totally fine. With it closed you can watch the pressure of the high side as it's filling with the A/C running.
Thank you for the video. I have cheap gauges from Amazon and someone had commented to snug up the connections with pliers because of the cheap seals in the fittings. 6 mos later, second time around, I forgot and leaked my Freon. Do you think I lost any oil?
Wow, great advice, I'll have to check mine! I'm not 100% sure. Probably Lost a little, but unless you're changing a component you shouldn't lose all the oil. I also misspoke in the video, pulling a vacuum will not remove the oil. It might be a good idea to add a little, but not the full recommended amount. You might do a little more research or ask a mechanic just to be sure as well. Thanks for watching!
@@EYVOAuto Thank you for the quick reply. Even after snugging the connections with pliers, the cheap seals only slightly compress and then you can loosen very easily by hand.
My system takes 7oz of pag 46 oil. If I add a "little", do you think 1oz is enough? Too much? Thx again.
Honestly if it were me I would probably add one PAG quick charge can. I think they contain 2oz of oil and a little freon. But again I'm not a certified mechanic so might be worth asking one just to verify
@@EYVOAuto Thank you very much for the quick response and all your help.
If the valves are closed like you say to do at 6:12, why would the gauges ever change? The lines are closed off from the system so how would it ever lose pressure?
I cant wrap my head around this, please advise. Every video I have seen says to do it this way. My car doesnt leak by doing the method everyone says, but once I put freon in, it leaks out within 2 days. The vacuum test, done the way everyone shows doesnt show me that it has a leak. And I believe it is because the gauges are closed and it will never identify if there is a leak.
Great question! None of the valves open or close the pressure gauges directly, they're just part of the manifold and read the manifold pressure on the low & high side. The valves on the manifold only shut off the center yellow line from the valve side. If they are shut and the hoses are connected, with the hose-end valve open, the gauges will read the system pressure since that is what the manifold is sealed off to. Make sure you're leaving the hoses open and just shutting the valves on the manifold for the test.
The valves on the manifold only shut off/open any in/out flow from the outside world. The valves on the hose-ends open/close the hoses. The gauges always read the pressure of the manifold and aren't turned off or on by the valves.
Sounds like you may have a very slow leak that might not be detected by just a 45min pressure test. I'm not a certified mechanic but you might try adding some UV dye to the system and see if you can find the leak using a light. The high side is under a lot of pressure so it could be leaking out there more easily when running.
@@EYVOAuto awesome explanation. Thank you. Totally makes sense now.
Sounds like your leak is in the valve. Won't show up in a vacuum test because you are using it
@@EYVOAuto It sounds like his leak is the Shrader valve namely the A/C System Valve Core. Here is the part from Autozone: Santech / A/C System Valve Core Part Number: MT0064-4. And make sure the Valve Core has the caps on. The caps are marked H high side and L for lowside. A/C System Valve Core and Cap Kit Part Number: MT29 . You can use a different brand if you want.
Very informative unlike most videos on u tube. THX
Thanks for watching!
Hey Man I’m not getting any vacuum I opened the gauges and left it running for about 45 mins and still at 0 turned it off to see if I’m still getting a vacuum and nothing please help brotha I live in az and it’s hot
Great question! There's got to be a massive leak somewhere! Did you get it figured out? Sorry for the slow response
What if I'm just topping off my freon, how do I know how much refrigerant I need to buy ?
Is the vacuum process necessary?
Any advice appreciated, Troy
Did you have freon in the car when the vacuum pump was running? If so, why freon was not coming into the vacuum pump or just came out?
Nope, no freon left in the system. Only reason to pull a vacuum is when the system is completely empty and has been opened to the environment, such as after a repair. It's to evacuate all the air so you can pull freon into a completely empty system. To remove freon before opening the system, like to do a repair, you'll need to take the car to a shop to have it evacuated and collected.
The oil does not get removed when pulling a vacuum.
100% correct. I definitely misspoke in the video. Pulling a vacuum does not remove oil, that's why most compressors come prefilled.
Newer vehicles are using r1234yf freon very expensive but taking it to a shop for recharge is 600$ also scotty kilmer says you dont have to hook up to the high side only the low side to evacuate the system & as for adding oil most of the freon already has oil in it.
Freon with oil in it and/or stop leak is roughly twice as expensive. I refilled an empy system for 3 small cans of R134a at $11 a peice from Orielly's. PAG oil was $9.99 and I have half of it left and half a can of freon left as well. Roughly $50 total. IF you don't need the extras don't dump them in your system. Keep it clean and mean. I'm still running good on my 2001 compressor. The condenser met a deer and neither of them speak anymore.
Man r123yf is ridiculous. I hate the day when I purchase a car with that stupid gas in the system. Also the little cans for just regular r134 are pretty price, so buying one with a little bit of oil in it just shoots up the price. I always add oil separately and look for cans that are pure gas and no other additives.
@@packrat9433 I noticed this as well when recharging my system. Hurt a little bit spending $12 on a 3oz can of freon +2oz oil... but in the end it was still cheaper than taking it to a shop!
Putting the system under vacuum does not remove the oil already in the system, that is not correct.
Thanks for the correction! I definitely misspoke. Pulling a vacuum does Not remove oil from the system!
All car ac systems are OPEN systems, they are not completely truly sealed as they have rubber O rings that will shrink and dry over time releasing gas gradually. This is normal, pulling a vacuum on a system that has lost its R134a gas is superfluous. Vacuum the system, and add new R134A gas to spec. If the system is normal that will do it, if not then you have bigger issues.
Do I need to do a vacuum the system before I replace my AC Compressor?
Yes, you will need to take the car in to a mechanic to have the Freon removed properly before replacing the compressor.
Then you will need a vacuum in order to refill the system after the compressor replacement.
The vac pump does not suck out oil
100% correct. Pulling a vacuum on A/C systems does Not remove any oil in the system
Very nice. Only there is a problem that oil so I can add it on gauge. There isn't oil in a bottle I can add on gauge.
What does it mean if the freon isn't being sucked up by the gauge?
You pulled a vacuum on system and then verified no leaks. How do you know how much R134 and oil are present in the system before you begin adding R134 and oil? What am I missing?
If you have to pull a vacuum, there is no refrigerant left in the system. You have to pull a vacuum when it is empty in order to remove the air and refill it. There is a sticker under the hood telling you how much refrigerant & oil the system requires.
This is a well done, educational video. thank you!
The vacuum does not pull the oil out of the ac system
Actually, you're right! Did a little bit more research and while the vacuum may remove the moisture it does not evaporate the oil. What removes the oil is when you have a leak in the system over a period of time or if you replace a major component. Best idea is to add a tiny amount when adding freon to replace anything the system has used, but no need to refill the entire amount upon a recharge unless you replaced a major component and it's not prefilled.
Hi, I'm confused as I've read some of the comments here and seems this procedure(performing a vacuum in system) is only done when a new component(new compressor) was replaced. My vehicle doesn't have cold air and whould like to add r-134u with a UV dye in it, to check for a leak. Should I vaccum the system? Thanks for the video*
I think you can still purchase the r-12 from Mexico. You'd have to drive down across the border, but I think you can still find some down there.
Thank you for that information you shared with everyone Thank you Again
Thanks for watching!
Oil has to be low pressure port or high pressure port??
Low side
Thanks a lot
Where do you buy nitrogen to pump up the pressure to test with bubbles?
Great question! I'm not sure...
While adding refrigerant, what would cause the psi on the high pressure gauge to go really high (400-500)? The high pressure side was closed the whole time while adding refrigerant.
A blockage somewhere. Expansion valve is common.
Freon: How do you add Freon when the compressor won't turn because of low freon?
What gauge do use for r134a?
thanks for the step by step information but I would love to see how to bleed the air. thanks
Great question! There is a little schrader valve in between the blue & red valve handles, under the viewing glass. You'll remove the stem cap & push it in until refrigerant comes out. Once bled you can open up the port & let the refrigerant flow in air-free.
Vacuum pump DOESN’T get rid of oil! Shouldn’t effect oil charge at all, unless you replaced parts! Never add oil because you Freon was low! Never! That’s why when you replace compressors or condensor, you measure the oil you drain out of components!
Why do most people say not open high side on the guages when vacuuming? But you did
You must open both gauges when running the vacuum so it will pull a vacuum on both sides. If you don't open one, it will not draw a vacuum on that side & there will be air in the system when you go to refill it.
Refilling it is when you shut the high side and use the low side only with the A/C compressor running. That will move the freon from the low side to the high and begin to pressure everything up.
I have a question... first you put the coolant and then the oil...??? because the oil came out of my car when I changed the part..!!
Great question! I'd get oil in there and then the Freon since there's a lot of moving parts in the system that need lubricated. If you use oil charge cans you can get some of both at the same time!
Is there freon in the system or did you have it removed
My Camry had a clutchless compressor. Fun and different.
Nice! That would be the way to go
Did I miss something in this video,,? I didn't see any pag oil put into the system. Or is that not necessary?
Great question. I used a few PAG quick charge cans that were 2oz of oil and 1 or 2oz? of refrigerant. It's necessary if you change the compressor and it doesn't come pre-oiled. I misspoke when I said vacuuming the system removes the oil, it does not. But doesn't hurt to make sure it's topped off either
@@EYVOAuto Thank you for your reply. I've a question, I am replacing the rear expansion valve and O-rings bcuz I found my AC this summer blowing warm. Upon inspecting the right rear shock on my 2015 Town and Country, I discovered green liquid dripping from that expansion valve/Evap junction. I pulled it apart yesterday and sure enough, the aluminum ring with center rubber O-rings were deteriorated, thereby causing the leak. The evaporator is in great shape, and the expansion valve looks ok but I am going to replace that.
Now I imagine this must have been leaking some oil all winter. So I have purchased everything you have shown on this video, manifold gauges/hoses, vacuum pump, 2 new Schrader valves (bcuz I did see bubbles at the low port valve), three cans of 12oz R134a and an 8oz bottle of pag 46 oil. Bare in mind my van has front and rear AC. It takes 1150g / (2.53 lb) of freon, but at this point, I don't know how much pag 46 oil to add. So my question here is, being that this system was leaking gas and oil, How much oil should I add? I'm thinking, 3 or 4oz..? What say ye? Thx.
I all I want to do is check the pressure in the system can you tell me which ports to have open or closed. Do I start off with all ports closed, run the engine and AC for 5 minutes, then open all ports to check the pressure or just open the high and low at the ports and leave the ports at the gauges closed or open all ports to check the pressure?
If you remove a line or your system leaks out the freon. Do you need oil as well or just freon?
You'll have to draw a vacuum on the system 1st which means you'll have to add oil with the freon when you recharge it.
If the system is still charged, just low, you can add just freon through a quick recharge can.
Do i need freon can with oil if my compressor already has oil?
Nope! Just fill it with Freon only, drawing a vacuum will not remove the oil. I misspoke in the video and need to revise it.
it's only $20 to get certified, and it's an open book test.
That's good to know, I'll have to look into it! Can you do it online?
@@EYVOAuto yes, I used MAC online certification.
And there was a study book you can send for ,the questions at the end of the book , if you can answer them without looking it back up in the book , you will pass too . I still got mine ..the places I used to work for payed for all my certifications , but I've been out of the field a while now ..brushing up the memory a little ..
I know when you buy the AC pump it does come pre-charged with roughly 3 oz of oil in it I know you can add the oil too the pump itself but after you start to charge the r134a do you still need to put the oil in after so much refrigerant
Great question! I was mistaken in saying to add oil to the system. You'll only want to add oil if the compressor you replaced was not pre-filled or had less than the car's recommended amount. Drawing a vacuum does not pull the oil out. If you need to you can add oil at anytime with an oil injector or you can add it with a quick-charge can when refilling.
Allr videos i see, no one purges the yellow hose
Excellent video tutorial! Thank you so much. 😎
excellent, thank you!!
Thanks for watching! Glad it was helpful
I've seen videos and some say to open the red on the top end but some says to never open it. Which one is correct and why?
Why would you add oil to the system if you did not replace the compressor and even then the oil is added to the compressor it self which usually comes prefilled
Thanks for watching! I misspoke in the video, you'll only want to add oil if you're replacing the compressor and the new one did not come prefilled. A leak will also cause some of the oil to leak out, but not necessarily the whole amount. However, I was incorrect to say the vacuum will remove the oil, it evaporates moisture not oil.
How to know if compressor has oil? And when to add oil in ac system? Every after vacuum?
Okay, so I messed up in the video by saying you need to add oil. If your compressor did not come pre-filled you will need to add. If it did, you are good the vacuuming will not remove the oil. Now a high pressure refrigerant leak will remove a lot, so if you just replaced lines due to that, add. Talking to my mechanic buddies it's a good practice to add a little anyways to just top it off, again if you didn't change a major component or it didn't come pre-filled.
@@EYVOAuto okay. Thanks a lot mate
excellent diy explanation
So if it is holding a vacuum for 45 minutes, where did the original freon go?
Are there different sized values that is used on the Freon recharge can which the yellow recharge line connect to? I bought a Freon recharge can and a valve for the can to connect to my yellow recharge line but the yellow recharge line connector does not screw on.
Thanks for watching! That I am not sure about, it seems like all the quick charge cans I have ever used have been the same size. I know some are self-sealing and others are the puncture-type cans. It you're using a puncture-type can, they make an adapter you can screw onto your yellow line or quick-recharge valve and then into that can that will break the seal - only problem with those is you cannot unscrew the can until it is empty since they do not seal back up.
Could you send me the information for the gauges also for the vacuum pump I would like to purchase identical or should I say the same like you?
If you have a harbor freight close by, you can get the same vacuum pump and gauges with two year warranty
I am trying to do it on my car following your video but I ran into a problem that the vacuum is not going below -26. Is that enough? It does hold vacuum for 45min like you said but I’m a bit worried. What should I do?
As long as its holding that pressure your fine. Thats an issue with the pump being weak itself.
@@julianhernandez6404 Or maybe a not very accurate manifold gauge.
Totally agree with the comments. You want to draw a vacuum and you want it to hold for some time before charging, just to verify there are no leaks. Could be an inaccurate reading on the gauge or could be that's all the pump will give. Either way you should be fine for the recharge as long as it holds -pressure.
@@EYVOAuto Thanks for the reply guys. I ended up postponing the project after getting a new pump and manifold line. And followed your instructions properly. Later while I tried to recharge the ac and connected Freon can...it only sucked in a tiny bit at the beginning and then stopped taking in any freon at all. Treid it multiple time with multiple ways without yielding any result. It feels like there is an obstacle that is not letting the gas go in. So next summer I'll probably replace the entire A/C system on my car.
Excellent presentation.
Thanks for watching!
When you add the oil to your AC system do you do it the same way you put the r134a in after you put so much freon in it
You can add it that way if it is in a quick-charge can. In liquid form, with a charged system, you'll have to use an oil injector. I misspoke when I say drawing a vacuum will remove oil, it does not. If your compressor / major component replacement comes prefilled you should be pretty close to the correct level. Now, if you had a large leak (broken hose / evacuated it quickly, etc.), this will remove some of the oil. Where I did no mechanical work to my A/C system & had a leak, I topped it off with oil just to be safe. Still working great!
You DON'T add oil unless you replaced a component within your system that contained oil. Too much oil in the system is bad for efficiency.
How did you put the oil in and did you put the oil in after the freon
You can indeed put r134 in a r1234yf system
Thanks for watching! While I’m not a certified mechanic, It’s probably best to stick with the refrigerant specified for your system to ensure proper operation.
Um vacuuming the system down does not take the oil out of the system.
Great video; thank you for sharing
Thanks for watching!
Thank you
Thanks for watching!
Hi how can I top up my ac and wha pressure is usually use
Hi great question and thanks for watching! To top off a low, non-leaking, system you may want to just use a quick recharge can / system and follow it's instructions. That'd probably be the easiest. Now for refilling an empty system, there should be a sticker under the hood telling you how much refrigerant to use, oil, and some pressure guidelines which vary slightly depending on the temperature outside...
Why is my high pressure barely goes up but low pressure goes up really fast?
May i have an indication of the vacuum pump you used. Will 1.8 CFM work?
Here is the link to the exact kit I used. It is a 4 CFM. If you don't want to buy one, you can "rent" one from O'reilly's / Advanced Auto Parts that will work great as well. I'm not sure what size theirs is.
1.8 cfm should work; it would just take longer, maybe an hour of suction instead of 30 minutes, but the 4 cfm is safer, quicker, and better, and you can probably borrow one from your auto parts place.
Is there anyway to tell how much oil is in there?
I have been doing DIY work on my cars for two to three years and have not seen a definitive method of finding out how much oil you have left. There is charts that tell you how much to add after replacing parts, but thats about it.
Great answer, thanks!
Some say you can dump the compressor out and measure it then add accordingly. But most new components will note how much oil they are prefilled with. Pulling a vacuum does Not remove any of the oil.
I love your video, I have a question, the oil has to be pour only when vacuum down or every time when charging Freon?
Hi, thanks for watching again! You'll have to add the oil after vacuuming the system, when you go to charge it again. You can either use actual oil and an oil injector or you can use an oil charge can mixed with a little bit of Freon. The oil charge cans are the easiest, but also the most expensive - they are different from the Freon cans. You car should say on it or in the manual how much Freon and oil it takes - make sure you put that amount in for it to work properly for a long time.
I was always told vacuum does not pull oil
Excellent. Thanks!
Thanks for watching!
Hello and thanks so much for your videos, they're very helpful. Have a question though; after vacuuming the system and verified that there's no leaks, i connected the can of refrigerant and nothing happened, seems that the can is not puncture good or something like that because I have no flow of refrigerant whenever I tried purging the air out at the end of the yellow hose on the manifold. Any ideas??
Did you ever figure this out? I’m having the same problem and can’t figure it out
Yes, I just recently did, I saw a video where they're using a different tool to puncture the can on the side, it really helped me. The only diwn side is that you can't use the can partially, once is punctured, and once you take the tool off the can, if there's refrigerant left in the can, it goes to waste.