How To PROPERLY Flush and Recharge A Contaminated AC System.

[Music] [Laughter] all right guys so today i'm going to show you guys how to flush an ac system there are two main reasons really why you would ever need to flush an ac system the first and most common reason is going to be a compressor failure if your compressor fails typically it's going to send metal shrapnel throughout the entire ac system you're going to have to get all those metal particles and all that garbage out of the lines before you put a new compressor on otherwise you're going to destroy a brand new compressor the second reason you would ever have to flush an ac system like in my case is basically the person that was working on it screwed up so like i alluded to a second ago the ac system in this car that we're going to be dealing with in this video is an ac system that i myself screwed up basically to make a long story short what happened was a couple years back i rebuilt the ac system in this car new lines new condenser new compressor the whole the whole thing basically with the exception of the evaporator i installed all brand new motorcraft from ford parts you know brand new compressor brand new lines yada yada got everything working everything worked great except for the fact that the ac compressor that was brand new from ford leaked um so i had to go through get a warranty compressor through ford installed another brand new ac compressor on the system when i did all this each one of those compressors came pre-charged with oil so the first time i changed the compressor when i changed all the lines at the condenser and everything the system had the correct amount of oil in it everything was fine when i changed to the second compressor the second compressor also came pre-charged with seven ounces of oil the the system capacity in this car is only eight ounces so i effectively had twice the amount of oil what i should have had in this car and like i said it's 100 my fault as far as flushing these systems guys does not matter if the system is overcharged or full of metal shrapnel or anything like that the procedure is going to be exactly the same no matter what your situation is if you have to flush the system so before you go ripping and tearing and open your system up take a look at everything and try to establish what direction the refrigerant actually flows in the system so for example my compressor is down here at the bottom this line right here loops around and comes over and goes into the condenser over here so this line is the outlet and it flows this way toward the front of the car so when i flush this line i want to flush it the opposite direction that it normally flows so you're going to back flush everything the thing is if i flush it in the direction of normal flow if there is metal garbage or shrapnel or whatever in this line if you flush it forward you're just going to drive it further into the line if you flush it backward you're going to drive all that stuff back out of the line the way it came in in my situation because i'm mostly just flushing oil it's not a big deal but like i said if you're dealing with a contaminated system you have to figure out what direction it flows in and how to actually back flush everything don't drive it further into the system so the first thing you guys need to do is you need to take the vehicle somewhere and have the refrigerant properly recovered have somebody pull the refrigerant out of the system have them pull a vacuum on the system that way you can bring the car home or wherever you're working on the vehicle and then you can go ahead and pull everything apart so the way that i am flushing this system i am flushing every component individually so what i'm doing is i'm pulling all the lines the dryer the compressor as well as the condenser the only thing that i'm not removing from this car is the evaporator inside the dash and the only reason i'm not removing the evaporator is just simply because it's so much labor for me to remove this evaporator it's right next to the heater core in the in the hvac box in the dash it's probably between four to eight hours of labor for me to replace this thing or at least you know take it out to clean it so in my situation i'm flushing everything individually that way i can tell if the components are actually clean or not so as far as flushing individual components guys i'm going to show you how to do it on this dryer do not flush a dryer just replace it like i said my system is already put back together therefore i don't have any hoses to demonstrate on so all you're going to do is take the end of your hose and take your flush and stick it in the end hit the trigger if you're using the aerosol the end of the hose will have a rubber seal on it so it should seal and you're just going to wait for it to come out the other end obviously like i said you're going to do this in the opposite direction of normal flow so you're going to flush the solvent backward through the system if you are using a pressurized container to flush out everything those are pretty simple as well all you're going to do is unscrew the can off of it dump your solvent into the can thread the can back on hook it to shop air and then you can take the end of the hose stick it in whatever hose that needs to be flushed flush it back flush it that way it's really just going to depend on whether you're using aerosol like i am or the you know the higher grade professional style tool once you have the solvent run through everything guys the next thing you need to do is flush everything with compressed air take everything off run compressed air through everything forward backward you want to make sure as much of the solvent is out of the system as possible um the solvent does not lubricate so if you leave the solvent in the system it's going to cause damage to the compressor because it doesn't lubricate the other thing is it doesn't cool so you may or may not have cooling issues depending on how much solvent you have in the system i've even read things online from uh four seasons who makes ac components they said any anything that you flush with solvent they want you to run compressed air through it for 40 minutes to make sure that there is absolutely zero uh solvent left in the system okay so let's go over all the things in the system that you cannot flush first of which the condenser you cannot flush the condenser i do not care what anybody tells you don't do it just replace it because first of all most of the condensers that are out on the market range between 50 and 150 dollars how many cans do you think i'm gonna have to run through this thing at 25 bucks a can to get this thing cleaned out just replace it it's going to be cheaper in the long run to replace the thing the other thing is even if you want to flush this thing the big problem is all these little tubes that you see here like all these tubes along the side this is actually what carries the refrigerant these solid tubes in the middle the passages inside those tubes are extremely small so if i try to flush this backward over here on the side if i try to run solvent backwards through this thing i have to get solvent all the way through this and out over here guys it's never gonna happen it's gonna save you money and time in the long run to just eat it and replace it if your system is contaminated that's what i did because i have no idea how much oil is in this thing i can't get all the oil out of this thing so therefore for 50 bucks i'm just going to replace it and move on next thing is is going to be the accumulator the dryer whatever you guys want to call it basically there's a bag of desiccant in the bottom of this thing that it absorbs any moisture that naturally occurs in the system while the system is in use if there's garbage in the bottom of this container you will never get all the garbage out of the bottom of this thing just replace it these things are this kind of like the uh the condenser i can buy one for this car for like 20 bucks again a can of flush is 25 so just spend the money replace these things the next thing you cannot flush is going to be either the orifice tube or expansion valve depending on the uh the type of system that you have this is an orifice tube system and if you guys look at this thing it's essentially it's a filter for the system so if there's any garbage that makes it through the condenser it's gonna get caught by the uh the orifice tube and you're probably gonna have some metal particles and metal garbage stuck in the orifice tube the orifice tube for this car is six dollars just replace it you'll spend more on flush than what you will just replacing it next thing is any line with a muffler in it all the recommendations that i saw online that any line that has a muffler in it needs to be replaced um there's there's no guarantees that you're gonna get all the metal garbage and all the contamination out of a muffler i did not replace the muffler in my case because i just simply had too much oil in the system so i flushed my my line that had the muffler in it i just flushed it out both directions made sure that the flush solvent came out clean and clear on both ends and blew it out with compressed air and set it on its way it's my system works fantastic so the final thing you cannot flush guys is going to be the compressor the thing is with the compressor if you try to flush it with the solvent the solvent is going to basically clean out all the oil that's in the compressor and there's a potential that you could still have residual solvent in the compressor and when you go to start the system up it's not gonna have any lubrication it's just gonna have solvent in it so nine times out of ten if your system is contaminated with metal particles and just you know the black sludge or the the black death as mechanics call it you're replacing the compressor anyway so there's no reason for you guys to flush it um the rest of the lines you know the evaporator all that stuff you can go ahead and just run the flush through it it's going to take some time but these are all the things that honestly just replace it i don't care what it costs it's going to cost you a fortune in flush rather than you know a fortune in parts now as far as flushing out my system i'm starting with the evaporator in the dash and the way i'm doing this is i'm running the solvent backward through the evaporator so what that's doing is it's going to break loose and clean any of the gunk that's built up in the evaporator my evaporator flows in the bottom tube out the top so when i flush it i'm going to flush it in the top and out the bottom just reverse of normal flow my recommendation is if you're going to use these aerosol cans like i am do the evaporator first because the evaporator is going to take a lot more solvent than what you think and the hoses really don't take much solvent at all to get them cleaned out so you're going to use the majority of your cleaning solvent on the evaporator so do that first while the cans full once you have each component completely flushed out with the solvent the next thing that i did was i took shop air and i ran shop clean dry shop air through all these lines through the evaporator through all this stuff to try and remove as much of that flushing solvent as you can yes the vacuum that you're gonna pull on the system will boil off the solvent but if i can remove the majority of it with compressed air i'm gonna do that you need to get all the solvent out of the system so before we add oil to the system we need to spend a minute actually talking about oil so all oem manufacturers that use r134a all recommend some sort of peg oil pag oil comes in three different viscosities there is a peg 46 which i have here there is a peg 100 there is also a peg 150 that refers to the viscosity like i said of the oil now the oil that i have here also has uv dye in it so you can get peg 46 in clear you can get peg 46 with uv dye the uv dye just makes it easier to find leaks now going back to viscosity so if you take a system that's designed for pack 46 and you put like peg 150 in it the system is still going to work the compressor and everything's still going to function like it should what you hit may have issues with is the system first of all when the compressor turns on it's going to require more horsepower from the engine than what peg 46 will because it's a little bit lower viscosity second thing is it may not cool quite like it's supposed to so if you have cooling performance issues you may have used the wrong oil something to keep in mind in addition to this if you have a hybrid or electric vehicle they also make a dielectric peg oil because the ac compressor in hybrid or electric vehicles is driven by an electric motor it's not driven by uh you know the serpentine belt on the engine so they have a special oil just for hybrid electric vehicles that if you guys have one of those you need to buy the right oil for it in addition to that if you guys have the newer refrigerant the 1234 yf they have they specify a certain type of peg oil for those systems as well so as you can see there's a lot to the oil what i'm going to do for you guys is down in the description i'm going to take you to supercool's website on supercool's website they have a year make model look up and what that will tell you is they will tell you the type of oil that's required for your system the amount of oil that's required for your system and then there's other general uh ac system specifications listed on there so rather than me uh you know trying to make recommendations in the video i'm just gonna send you over there and you're gonna get all the information that you possibly need now at this point i'm gonna put my ac system mostly back together um putting the condenser back in putting the hoses in the only thing that i'm leaving disassembled at this point is going to be the compressor and possibly the dryer depending on what style of system you have so now that you know the quantity and the type of oil you need i'm going to tell you guys how to actually add it into the system because believe it or not each system may be a little bit different depending on the type of compressor you're dealing with whether or not you have an orifice tube or expansion valve in your system so first thing we're going to go over if you have a variable displacement compressor typically they have a plug on the back of them that you can tell if it's a variable displacement or not those compressors also typically have some sort of drain bolt on the crank case to drain the oil out in that situation those compressors all you're going to do is you're going to take the total amount of oil required for the system and dump it into the crank case put the plug back in it send it on its way that setup's about as easy as it gets this vehicle that i'm dealing with in particular this is a ford fs10 compressor which is a cycling compressor it's not variable displacement most of the the older stuff like this is not variable displacement so what you're going to do in those instances on a non-variable displacement compressor that does not have a crank case you're going to take half of the required amount of oil and dump it in the suction line of the compressor you're going to take the other half of the oil charge for the system and you're either going to put it in the dryer or the evaporator and that is going to depend on whether or not you have an orifice tube or not so no matter what if you do not have a crank crank case half the oil goes in the compressor this car has an orifice tube set up so half of my my other half of my oil charge is going to go in my dryer so if i had a vehicle with a thermal expansion valve you are not going to put the oil in the dryer you're going to put the oil in the evaporator in the dash the other half of your oil charge what can happen if you put the other half of your oil charge in the dryer on a thermal expansion valve system there it's going to take a long time for that oil to make it through the thermal expansion valve and the compressor may run for a period of time without good lubrication so thermal expansion valve put the half charge in the evaporator orifice tube setup put the half charge in the dryer no matter what unless it is a variable displacement you're going to put half of the charge in the suction line of the compressor so once you get your system all put back together before you start the vehicle up or start pulling vacuum on anything there's one thing you absolutely need to do no matter what type of compressor is in the vehicle you need to turn the input of the compressor in the direction that it normally rotates when the vehicle is running you need to turn it at least between 10 and 20 times what that's going to do is that's going to ensure that that compressor isn't going to hydro lock so because you dump that oil in the suction side of the compressor there's a potential that when the engine turns on and you turn the compressor on there's potential that the compressor could hydro lock and it's going to destroy itself if it hydro locks so what that by turning the input that's going to keep that compressor from hydro locking and just causing damage so make sure you do that before you know you start charging the system pulling vacuum you know driving the vehicle around in any way shape or form just make sure you don't have a giant charge of oil sitting in the compressor when you start it up alright guys so as you can see i've got everything all back together here now there's one major thing that you need to do before you just dump refrigerant in this thing and just turn it on and see what happens you need to pull a vacuum on the system so this is a vacuum pump and what this thing does is it will connect to the middle line or the yellow line on your manifold gauge set this is normally the line that you would use to charge the system it'll hook right to one of these vacuum pumps you turn on the vacuum pump open up your valves and just let this thing sit here and run for an extended period of time we'll get into that in a second so first of all why do you want to use a vacuum on your system well by pulling a vacuum on the system it's really going to do two things so the first thing is it's going to boil off any moisture that's left in the system so when you take water at room temperature and you expose it to a high vacuum level it will make that water boil so if you let the water boil long enough you will boil out all the water that's in the system so what that's doing for you is it's removing any residual water or moisture that's in the system so when you charge it you're only putting refrigerant in the system there's only refrigerant and oil in the system that's what you want you don't want any moisture in there because the moisture isn't going to lubricate the compressor like it should and it's not going to cool correctly now the main reason that we're using the vacuum for this video and the people watching this video is the vacuum pump will also boil off all that flushing solvent that i ran through the system and threw all these lines and threw the evaporator in the dash so by hooking up the vacuum pump running the uh the vacuum pump on the system it's going to boil out any moisture any flushing solvent and what that's going to do is that's going to ensure that obviously there's nothing in the system other than the refrigerant and the oil and that's really what you want as far as how long you need to run the vacuum pump guys the service data that i have on this car from ford says whenever you run solvent through the system you need to pull a vacuum on the system for at least a half hour i'm probably gonna do like an hour hour and a half just to be safe you really can't hurt anything by pulling a vacuum on it longer than what's really recommended like i said ford said at a minimum do it for a half hour so that's what i'm gonna do here guys i'm going to get this thing running get this thing going once i have this thing going i'm going to bring you guys back and show you you can also leak check it with a vacuum on it all right so i'm about done with the vacuum pump but don't just turn the vacuum pump off make sure you close your valves before you do anything with the vacuum pump so you're going to close both valves [Applause] then turn the vacuum pump off then what you can do is come up here and just watch this low pressure gauge and just make sure it doesn't move give it like between 5 and 20 minutes make sure it doesn't go anywhere if it starts bleeding vacuum off immediately you have a leak somewhere you need to find it to find a leak um in this scenario what i would do like if anything under here was leaking i would take some of my shop air and just charge the the system with shop air to put some pressure in the system so i can see where possibly is it leaking so once i have some pressure in it you know take some soapy water go around spray all your connections see where the bubbles come from and then go ahead and check that connection i'm going to let this thing sit probably about 10 or 15 minutes or so and then we're going to come back and i'm going to start dumping refrigerant in this thing all right guys so it's been about 15 minutes or so i fired the car up let the car run a little bit because i pulled the radiator out i want to make sure my cooling system was all completely bled out got all the air pockets out of the cooling system so i'm good to go there after i got that done i came back check my gauges my gauges are still showing about 30 inches of water which is really is about all the vacuum you can ever pull most amount of vacuum you can pull is 29 and a half so as long as you're holding after 5 to 15 minutes you're usually good to go on charging it so as far as charging it guys typically there's a sticker underneath the hood up here or down here somewhere that'll tell you the amount of refrigerant that the system will take in the case of this mustang so it takes 34 ounces each one of these cans is typically about 12 ounces so i need just under three full cans to fill this system so as far as the refrigerant obviously if you have an r134a make sure you're buying 134a if you have a newer 1234 system make sure you're putting 1234 in it and not 134a something to be super mindful of because recovering contaminated systems that are mixed with 134a and other refrigerants gets pretty expensive as far as the refrigerant itself guys i typically buy the cheap stuff the thing is when you buy the cheap stuff there's no extra oil there's no stop leak there's no other stupid additives that frankly i don't really think you need especially in my sort of situation because i know how much oil is in this system so i don't want to add extra oil i but my system has enough oil and it's to capacity at this point as far as oil is concerned i just want refrigerant so some of these cans will come with oil that will come with stop leak and they will not tell you how much oil is in the can so they don't tell you how much is refrigerant how much is oil so when you buy the uh so when you buy the cans with stop leak or extra oil you don't know how much oil you're putting in there the other thing is about refrigerant guys there's a bunch of stuff out there on the market that's oh it's synthetic refrigerant you know this is cold it's the coldest it does this it does that and blah blah blah there's a lot of marketing around refrigerant for some reason i'll be honest with you guys i think 99 of it is pretty much all bs um if your system is functioning and working correctly the system does not care what refrigerant you put in it it's going to get cold either way if the system works correctly go into any shop that buys like the big 20 pound containers of refrigerant for their ac machines ask them if it's synthetic and it's the coldest they're not going to know because typically when you buy those bulk containers all that marketing crap completely goes away so to actually charge this system guys all i'm doing i've got this can adapter it just threads on the top of the can the can adapter hooks to the yellow line that we use for the vacuum pump and then what you're going to do is once you have the yellow line hooked to the can thread the the top of the can down or the the adapter down onto the can i guess you're going to open the low side valve that is going to let the refrigerant flow into the low side of the system if you connect this up to the yellow line and you open the red valve the pressure in the high side is greater than the pressure in the can therefore you are going to empty the system and push the pressure in the refrigerant from the system into the can you will probably blow up the can that's why typically when you go to the store and you buy one of those ac recharge kits they only come with one hose because they only want you putting it in the low side it's kind of a liability thing so that's what we're gonna do so i'm gonna hook this thing up get this thing charged up and uh we're gonna see what this turns out like so that's going in guys the thing is the first can since you have the vacuum on it the vacuum in the system is going to pull a lot of this out of the can typically if the system's empty it's never going to let the compressor turn on if the pro if the compressor doesn't turn on as far as the cans are concerned it's hard to charge so i'm going to go in start the car up valves are open go in turn the ac on and we're going to start filling this thing all right so i've got everything all charged here are my pressures so my low side pressures at idle is running about 25 psi my high side pressure is about 175 psi both of these are sort of on the low end for my ambient temperature right now so my ambient temperature is about 80 degrees give or take so this thing should be running about 200 and about 40. it's a little low but i'm getting tons and tons of cool air out of the vents so i'm really not going to screw with it i'm going to leave it exactly how it is i have the right amount of refrigerant in it um if i rev this thing up you'll see the pressures change a little bit and actually if you look down below one of the uh ac lines actually has a bunch of frost on it so it's if i go much colder than what i am now i'm gonna start freezing up the evaporator and then i'm gonna lose all air conditioning so guys check it out i got the car running here and uh we're looking just under 40 degrees probably 38 37 degrees that's right about perfect overall super happy with how it turned out unfortunately you know i was the one that screwed it up to begin with but i made it right so it is what it is um guys as always i'll have links down in the description to the solvent to all the tools and then to the information that i talked about in the video as far as the different types of oil where it'll find all that stuff um as always guys if you guys like the video hit like you want to see more content go on hit subscribe thanks for watching guys [Music] you

Channel: Repair Geek

Views: 288,211

Keywords: air conditioning, compressor failure, ac system flush, ac flush, how to flush ac system in car, contaminated ac system, auto ac, auto ac recharge, compressor, dryer, orifice tube, oil charge ac compressor, ac system flushing, car ac system flushing, flushing contaminated ac system, flushing a/c system, flushing ac lines, ac oil charge, ac oil injector, r134a, 1234yf, ac flushing procedure, ac flush and recharge, ac, how to flush air conditioning system, contaminated, recharge

Id: N_msH6TX2W4

Length: 29min 42sec (1782 seconds)

Published: Sat Sep 03 2022