How To Recharge an A/C System Professionally DIY

hey guys I'm the 50s kid and in this video I'm going to show you how to recharge an AC system so for any kind of real AC work you need a set of manifold gauges like this you can get these pretty much anywhere they should be about 50 60 bucks they have these Quick Connect couplers and these ones actually these are automatic um couplers the manual ones actually have a valve on them so once once you hook them on you turn the valve down and it presses the Schrader valve these ones are automatic these ones when they lock down they automatically depress the Schrader valve and you'll notice the Quick Connect thing it stays up when it's not connected and it will only go down once you actually are on and connected on on the valve so that's kind of a cool feature which I really like so let's go ahead and hook these up to the high and the low sides the red is the high the blue is the low so first thing we need to do is locate our high and low fittings you want to go ahead and locate your AC compressor and then just follow the lines back you can see there's an in and out line you can see right here as we follow the line back we've got one connection it's actually got the H for high so I'm going to remove that and then over here this one has the L for low and I don't know if you heard that there was a little wisp of gases that's actually normal these things have O-rings in them and they're just you know just the nature of Schrader valves they do leak over time and that's why these things have O-rings they're kind of a secondary defense against uh refrigerant leaking out so that is normal a little bit of leakage as normal make sure before you hook any lines up that both of the valves are closed on your gauge set make sure all the hose connections are nice and tight you don't want any leaks because this thing will leak once you hook it up so let's go ahead and hook up the high side high side is the bigger one low side to the smaller one there are different sizes so you can't get them mixed up I just press down until that snaps on hook up the low so we have both valves closed but we're still getting pressure readings that's because both lines basically bypass that valve they go right to the gauge they're always live with the gauge these these valves on either side are what connect the this one connects the red line to the to the yellow input line this one connects the blue line to the yellow input line so really the valve is in here that's what's actually opening and closing this actually goes straight through to the gauge all the time let's go ahead and start the car turn the AC system on see what the pressure is read foreign on and I'm going to turn the AC on and we should have seen the compressor click on and yes we did and these are our gauge readings while the AC system is on and working as you can see this I'll tell you right now is low the high side should be here between 150 and 200 depending on how hot it is and the low side should definitely be over 30 PSI so the system's definitely low without a doubt we're low on refrigerant and that means that there's a leak somewhere so before I just fill this thing up with more refrigerant I need to find that leak and repair it otherwise whatever I put in is just going to leak out again so the way we do that is we inject UV dye into the system let it run and it will leak out wherever the hole is and I can use a special flashlight to illuminate that I'm going to use this product to inject UV dye into my system it comes with a little Quick Connect connector to just hook right up to the low side so we need to do this while the AC system is running and what you do is you connect this to the low port and what I'm going to do is pull back on this it's another quick connector I want to make sure that I've got it on there make sure I can't pull it back off and what I'm going to do is this cap needs to come off I'm going to I'm going to follow directions I'm going to push the button down for three seconds to inject the die two three there we go simple as that I'll kind of wait for the the rest to sort of boil out there get sucked out should be pretty good I put the Caps back on and we're just going to let the AC system run so I've been looking along these lines with my light and I can't really see anything except for right here where the cold valve is and I think that's that's basically where it's sprayed a little as I disconnected the injector so I don't know I can't find any other leaks I can't find any leaks of the compressor anywhere along the lines and from what I can see of the condenser can't really see any die there either maybe I suppose I could and clean the die away I don't know if that'll work looks like brake clean is working pretty well to rinse the dye off that I don't think I'm going to be able to get the dye out of out of the center that's just not going to work the only thing I can think is that maybe that Schrader valve is going bad a little um I had I had previously checked these pressures a couple days ago when I was kind of you know preparing for this video and at that point when I removed the the the cap I heard some refrigerant leak out and it's only been like I said a couple days since I since I had done that and when I undid that valve a couple seconds ago while we were shooting the video I heard that refrigerant hiss out again and I wouldn't have expected that much to hiss out in just a couple days or even enough to actually cause a hiss which makes me suspect that valve so because there is still a little bit of refrigerant in this system I need to go and get this evacuated by a professional it's illegal to discharge coolant into the atmosphere so go get it done by professional you can do everything else yourself you can recharge it and all that stuff yourself but you have to get a discharge by professional all right I went and got the system evacuated and it is reading is empty now which is good go ahead and hook up the charge line to my vacuum pump turn it on and we'll open up both ports all the way you can see that we're drawing a vacuum on the system you're not going to get a perfect vacuum at least I'm not going to get a perfect vacuum especially with mild pump here but it'll be good enough if you're not drawing any kind of a decent vacuum you might have to change your pump oil you want to let your system vacuum down for about at least 30 minutes it's been about 30 minutes so I'm going to close both valves shut off the pump and I'm just going to let this sit now for I don't know 10 20 minutes make sure that the vacuum just stays where it is if that needle goes back to zero we know there's a leak somewhere so it's actually been about two hours had to go to two different parts stores to get a couple of parts I needed so it looks like the vacuum has held which is good I think that proves by process of elimination that it must be the Schrader valve pretty certain that it's got to be these Schrader valves that are bad mostly because it's it's Schrader valves that actually are the most common failure for an AC system they just go bad over time that's why they sell little kits like these that come with replacement valve cores and a little valve core tool and actually new caps as well because you just want to have new O-rings if at all possible so I'm gonna go ahead and remove the old core and install the new one so this is what a valve core tool looks like it just has this little shape like this and you just kind of put it down in there I think I still have vacuum in this system but that'll leak out when I pull this valve core out just put it down in there unscrew it okay so that's the old valve core and this is the new one that came in the kit obviously a different one so bummer looks like I got the wrong ones here I'll just take my old one over to Napa and see what see what they can do for me all right I got the correct Replacements from Napa the guy actually showed me a picture of five different kinds of valve cores so I think it's definitely recommended you take your old one to Napa or wherever to find your correct replacement part I guess I'll just get this other one out of here might as well replace both you know all right so I'm just pulling down a quick vacuum right now um I all I don't need to do it for 30 minutes already did that before already dried out the system dried out the desiccant so now I just needed to just pull a quick vacuum make sure all the lines had vacuum in them so if you're in the rest of the country you have these style cans available where they're sealed on the top you need one of these adapters you basically you loosen it all the way out and you screw it down then you tighten it all the way down and that pierces the can and seals it at the same time and then when you open when you back it out again that's what releases the gas but I'm here in California and we have these new cans now that have they sort of have their own Schrader valve in them and so now you need yet another adapter in order to use these cans and that just kind of screws on and adapts to this older style thing now now for me in California when I put this end on I have to make sure that this is all the way down and try to do this quickly yeah okay that was good so it's all the way down it's sealed ready to go ready to hook up to this line so if you're wondering about adding oil I'll tell you on my system that there wasn't much of a charge left so the guy told me that barely any oil came out um if if oil does come out if you had a relatively large charge when the guy vacuumed down your system and and you know you could get I guess between an ounce or two of oil that comes out that's that's really just the the oil that's in the lines in the rest of the system most of the oil is in the compressor that's what the oil is for so it's not as if when you go and get your system evacuated down that doesn't pull out all of the oil that's in the compressor it just pulls out some of the oil that's in the lines and the and it doesn't make the oil evaporate or anything the refrigerant evaporates water evaporates when it's under vacuum but the oil the boiling point is still too high so the oil is still a liquid and the reason it comes out is just through the force of air that's rushing out of there so that's why you know a little bit of oil will come out but you know most of the oil is still in the compressor I think that's what confuses a lot of people you know they'll get their systems evacuated down especially when they're doing a conversion from R12 to R134 they'll they'll think that they need to put you know the prescribed amount of new oil into their system even even after it's all been evacuated or whatever and I think they end up getting too much oil into their whole entire system in that case when you're doing one of those conversions if you want to change your oil you've just got to drain it from the compressor you got to pull the compressor out and drain it then add the new oil in but anyway don't have that problem not very much oil leaked out so I'm all good I'm just going to screw this thing on attach it and we want to bleed this so there's air in this yellow line right now right so I'm going to open this up somewhat all the way and what we want to do is bleed the air out of this line you do that by opening this up until you see well we should have seen it might not be all the way out here that should be enough so uh it is illegal to uh vent cooling into the refrigerant into the atmosphere but there's an exception for when you're you're bleeding your lines so that was legal what I just did to charge your system you only open the blue side that's the only side that you ever open never open the high side so I'm opening this up all the way and just letting it fill I'll just kind of let the pressure equalize until it just it's not going up anymore you need at least I believe it's 25 or 26 PSI in the system before the compressor will turn on there's a low pressure switch that prevents it from turning on if there's not enough refrigerant in there so it looks like we're up around 30 which is good what I'm going to do now is start the engine we're going to use the compressor to draw in all of the refrigerant and I'll just be kind of turning a can upside down back and forth you know upside down and right side up a couple of times just get all the refrigerant in there it takes about five minutes or so so let's turn the car on we've already got the AC turned on you can see the compressor kicked on pressures drop the high side will be building and I'm going to take this can and shake it around turn it upside down as you can see more coolant goes in pressure goes up the compressor then pulls it into the high side and that's why the low side goes down can gets really cold if I didn't mention it before the sticker on the hood of this vehicle says that it takes uh I believe it was one pound nine ounces of refrigerant which works out to 25 ounces and I've got two of these 12 ounce cans so that's 24. that should be that should be enough honestly I don't think that extra one ounce is going to matter the pressures by the way should be between 30 and 40 on the low side and between 150 and 200 on the high side you can feel that this can is pretty much getting empty I believe it is empty okay yeah I believe it is empty so I'm gonna shut off my my uh low side very very important that you shut this off before you disconnect your can if you don't do that you are screwed you're gonna draw air into the system so I'm uh closing this down no way to avoid that got my second can I make sure that my uh my thing is all the way down so it's sealed make this sucker up we'll open it make sure you don't over tighten the yellow okay the yellow line there's an o-ring in there you don't want to crush it let's open that up all the way I'll bleed this line again just let a little bit of the air out and I'll open up my low side again we're just uh upside down right side up foreign pressure is going up to 200 almost I think the can's about half full still at around 32 psi on the low side that's good around 200 on the high it's where I want it to be I think it's going to take this whole can I think we're pretty much almost empty [Applause] RMC close off that low side close my can again no way to avoid that [Applause] there we go those are pretty much the pressures you want to see though I'll try to find a chart as well see if I can find a chart online because depending on what the temperature is outside the pressures are going to be different so there we go about 44 degrees super duper cold really awesome go ahead and shut the vehicle off remember to replace your caps I tried to use those new caps that I got and that kit but they are the wrong style I'm just continuing to use the old ones and now you too can recharge an AC system like a boss thanks for watching

Channel: 50sKid

Views: 574,874

Keywords: A/C System, Automotive A/C Repair, Automotive A/C Diagnosis, Do It Yourself, Auto Repair, Automotive A/C System

Id: QO1rH8Xzbtc

Length: 18min 3sec (1083 seconds)

Published: Sun Dec 27 2015