A/C Leak Testing, Repair, Evac and Recharge (ANY CAR!)

i almost want to change hey guys scanner dander here because i'm not dan i'm paul scanner danner is just a name my students gave me 15 years ago before youtube or anything anyway it is warm and humid today supposed to be 95 degrees tomorrow and my son jake my oldest son has this 86 nissan 300 zx and his air conditioning doesn't work so he's like hey dad can you fix my air conditioning i said it is that time of year everybody's looking for air conditioning repair type videos and let's do one on your car jake so that's what we're doing there are many different directions that i can take you and i think what we'll do first is let's just attack the problem at hand and see what we have and get you guys some quick tests that you can adopt for yourselves okay number one is when you have an air conditioning system that doesn't work is put your gauges on it actually i'm i'm kind of conflicted because that's not necessarily number one number one is you're inside your car you hit the ac button it blows warm right then what's number two you can come out under the hood and on this car it's easy to look at the front face of this compressor if this front face is not turning with the belt then your compressor's not engaging and then i guess step three would be connector gauges even though i said gauges is number one let's get a pressure reading but here's the thing when i deal with you guys who ask me questions about their ac systems the number one answer that i have in reply is i need pressures to be able to help you so you have to be able to get pressure readings um this gauge set i'm using is very inexpensive i don't remember where i got it but i think it was like 35 or 40 dollars so it's not really professional grade but i don't do very much air conditioning work anymore and this is a gauge set that anyone can afford um and you need one when you're doing air conditioning repairs on your own you need a good gauge set not just low side pressures but you need high side pressures these are on already the schrader valves are depressed check out the gauge zero nothing systems empty so we have a leak i was setting up for you guys and uh one of the things that i like to do is i want to be able to see all of the plumbing to see all of the plumbing i had to raise the car up in the air you see the jack and jack stand in the front and the reason i did that is i can't see the condenser it's like mounted like this way underneath and i want to show you guys what i see down there i i can actually see an area of a leak um so before we charge this with nitrogen and do the soap and water spray test which is what i'm going to show you guys let me show you what i found underneath when you see something like this on a condenser that's your leak that's at least one of the leaks and um i'm hoping when we do this there's a connection up at this top right corner now i can't really see what i'm pointing at um but in this top right corner there's a connection and a line and there'd be an o-ring there and i'm hoping it's just the o-ring and it's blowing over onto the condenser fins and it's not a condenser fault or leak in the condenser itself we're going to find out here shortly so all of you at home can do those inspections um it is important to see plumbing so you're gonna have plumbing from your compressor that's gonna run to the evap core inside the dash from evap core to compressor from compressor to condenser condenser back to the compressor and of course depending on your system there would be either a receiver dryer or accumulator dryer you want to eyeball all of those components that is a receiver dryer that's on the high side of the system it has a sight glass on it and that tells me a little bit about this system that this is a thermal expansion valve system they always combine receiver dryers with expansion valves that's inside of the dash it looks like i can't see the expansion valve but that's not a big deal but eyeballing your plumbing is important and you can see why i mean i didn't even have to do anything to identify that i have a leak in that corner of that condenser something else to point out this is an 86 and this has already been retrofitted and i know that because of the fittings that are on it so this would have been originally an r12 system and what what this had on it was the red and the blue caps right high side low side and those are your identifications right away that somebody has already retrofitted this to the r134a refrigerant you see the caps that thread onto the original r-12 fittings so i'm just trying to cover all my bases before we turn the camera on make sure i'm prepared for what i need to fix my son's car and one of the things that i researched was the type of oil because when you have a leak like that as you can see you lose a little bit of oil but the other thing is i have some unknowns here i don't know how much oil was put in this when it was retrofitted and so if i'm going to recharge it today and maybe fix an o-ring hopefully i'm going to add some oil to this and i wanted to know what type from memory way back in the day i retrofitted hundreds of these and i remembered using ester oil and i couldn't remember why ester oil was preferred over the pag oil so there's your two oils there's your peg and ester and there's different weights for these when i did my rv and i did caleb's jeep i believe we used a different peg number for both so make sure you do your homework as far as the oil viscosity and and what you should use it's that number after the peg but we're going to use the ester for this and then i did a google search to remind myself i just did a r12 to r134a oil recommendation that's all i typed in and it says ester oil is recommended by most aftermarket manufacturers and rebuilders ester oil mixes with and is compatible with mineral oil ester oil can be used with r-12 and r-134a refrigerants and ester oil is not as harsh to o-rings seals and paints as peg oils so when you retrofit these we i sat in some classes way back in the day and what they did is they put mineral oil on like a paper plate and then they sprayed some r134a refrigerant over top of it so mineral oil is the original r12 oil and when it's exposed to r134a refrigerant it turns into like a paste almost like a glue so it it it's not compatible and you have to when you retrofit these you have to add an oil that's compatible and you can see why ester oil was the preferred one now pad can be used as well but apparently ester oil uh it says it can mix with it i'm not the chemist so i'm just telling you what we used and what is recommended you guys do your research on what type of oil you want to run if you're doing a retrofit for when we're done i'm just going to add maybe two ounces of ester oil to this you know of course depending on what we do if we have to replace the condenser each component you replace is going to require a certain amount of oil and we'll cover that when we get there if it's just an o-ring leak then i'm not just going to blow refrigerant in it i'm going to put two ounces of oil in it too just because of unknowns i don't want to over charge it with oil but i don't want it starving for oil either let me start this real quick and i'll show you the front of this compressor just watch this here when i start it and i'll turn the air on too [Music] notice again how the front face of this compressor is not turning so if you guys are going to message me and say hey my air conditioning is is warm it's not blowing cold and and i have you know 70 pounds of pressure in the system well 70 should be enough to engage the compressor i'm gonna ask you hey look at the front face of that compressor not the belt part but the front face is that front face spinning with the belt it should be turning right that should be turning along with the pulley and the belt if it's not that compressor's not engaging and then we do power and ground testing and things like that i got a lot of other videos on testing ac systems for no power to the compressor for faulty compressors and i'll put a list here for you guys to look at those all right so my son's car you'll hear an rpm change with the blower off listen blower on it's anticipating a load for the ac compressor pretty crude system as far as that goes because there is no load right now uh ac buttons right here and did you see that gas light just come on it says gas and there's a light that came on now if i shut the car off restart it the gas light is no longer on so it's almost like the system even in 86 is recognizing that it's low on charge there'd be no other reason to have a light above a indicator that says gas in my opinion than the fact that you know it's low on refrigerant but that's your ac button no change of course because there's no pressure in the system and i just found that fascinating that this 86 has a light that says gas and man you talk about an electronics nightmare that would be this car let's blow some nitrogen in this and locate this leak for sure let's pinpoint the area where it is from my last video where i started using nitrogen i used to uh air leak check with compressed air and of course air and the refrigerant oils become acidic and i understand the feedback i got from air charging i still think that if you're a do-it-yourselfer and you have a car like this an old car and you don't have a nitrogen tank that you're still better off using compressed air in the system over top of charging it with refrigerant to find a leak you have a gaping hole in the system you blow a can in to locate a leak what did you just do you just dump that k into the atmosphere so just make sure you evac the systems very very well when you're done get all that moisture out of there anyway that being assad i'm using nitrogen and one of you guys commented about me not having a protective boot around this it's metal it covers this valve and it's important because if this bottle would fall over and knock the end of that off you're talking about what kind of pressures does this thing have i forget let me connect to my hose and i want to just get get a pressure reading i forget i think it's like 2000 psi that's in this tank and i have my valves closed up on my gauge set right now that's important those are closed if i turn this guy on yeah i got 1500 psi i have this regulated at 200 that's what's coming out this is 1500 psi so the point was if this falls over and breaks the nozzle off we have a cannon we have a rocket and it's gonna go somewhere so it was a legit um comment and i ordered one the one i ordered didn't fit so i had to send it back and i forgot about it and never ordered another one so this is my safety right now if i knock the bottle over while we're working that's not gonna happen this is not ideal guys um think about safety when you're dealing with stuff like this and having that metal container or coupler around here protects this valve from being broken i think that's important so 200 here is what i have this regulated at let's blow some stuff in the system now as far as which side to add to it it does not matter there is no low side and high side of a system right now with the system off so i can put it in either side i'm just going to open up my high side and we're gonna put i'm gonna start with like 150 psi actually we probably start with a hundred just to see how bad of a leak that is so those are now closed um like in between 100 and the next line up so what's that i don't know that's 125. so in between those two at least from my angle we'll kind of keep an eye on that maybe look at this gauge we get more accurate number where we at 101 psi so really we're looking for decay how fast does this decay is why i'm being critical in that number okay and of course where i'm spraying first is my visual inspection showed me where that leak is that's where i'm going just using a soap and water mixture here oh jake is in luck right off the bat it's the o-ring that's awesome no condenser needed yeah so guys look this right here is why you never charge an ac system with refrigerant to find a leak why would you when you have stuff like this available to you again at least charge that system with air pressure to find it don't pollute the environment with these refrigerants i don't care about the acidic level of the ac system and that when you charge these with compressed air you make acid if you don't get all the moisture out i don't care i'd rather you do that then then contaminate our environment with these nasty refrigerants i'm using nitrogen it is the preferred way but that is an o-ring failure for sure that's awesome that's awesome okay so we're going to spray the rest of the system down that i can see and make sure we don't have any other leaks we'll do some decay measurements too that's down to 100 by the way so that's in itself telling us we have a leak and we'll we'll use that when we're done as well to make sure we don't have any other ones after we fix that one down there but we'll spray the rest of the system but one of the other things i like to do in this case is i want to make sure the compressor can engage and now we have pressure in the system and we can verify that the compressor engages with pressure and the reason you want to do that is you don't want to sell a customer if this is a paid job you don't want to sell a customer a repair for a leak say it needed a condenser which wouldn't be cheap only to find out when you're done that there's no power getting to your ac compressor and you want to know that up front so i have enough pressure in the system for that compressor to engage what we want to do is watch the low side and watch the high side and it should be like a four to one ratio roughly low side should drop real low high side should climb compressors should engage so see if you can get that for me closing this off taking my center hose out of the picture because i need the room all right so i'm going to start it real quick and you're going to tell me what this drops to and what this climbs to can you do that yeah and then watch that front face [Music] what's our prep yeah sweet the front face engaged and they kind of stopped for a second i the front face engaged and stopped because i pushed the ac button on and off so it was already on yeah yeah so that was okay um i like 40 and 170 um when we uh sat through classes it's a compression ratio and they gave us a number and i don't remember i remember them saying like four to one or five to one four to one like if you did 40 and 180 that'd be four that's a four to one ratio so that's kind of what we're looking for here what that tells me is is a few things number one it tells me electrically everything is working like it should be for that compressor to engage and number two it also tells me the compressor is able to do its job so if you're you're working on an ac system and it needs all these components and you don't want to find out when you're done that your compressor is garbage and can't do its job and this is one way that you can do that without refrigerant now the downside of that test is the nitrogen isn't carrying the oil through the system and lubricating the compressor so you don't want to do that test for any long period of time but that's a real good quick test to tell you uh compressor function and again electrically how is that doing now if you had 100 psi in your system like i do and you did that test and the compressor does not engage what do you do now as a technician what do you do well even as a do-it-yourselfer that maybe is charging a customer what you do is you stop and you say you get back on the phone and say mr mrs customer i need x amount of time usually an hour diagnostic time would cover it at least get the okay for that that you now have to attack the electrical system on this ac system and find out why that compressor is not engaging and that's on top of fixing your leak anyway moving on um what do we do now i have 100 psi in the system let me address this question can i charge with more than 100 psi absolutely on really hot days high side of this system is going to see 300 psi low side of the system is generally around 30 to 40 psi so it's not going to see that kind of pressure however when you shut the car off pressure's going to equalize on a real hot day with this engine up to 230 degrees and the hood's shut and the ac off you can easily see 200 psi up at the evap core even though that's the low side of the system so fire away man 200 psi go for it if you can't find a leak at 100 psi then put 200 in it if you can't find a leak at 200 psi between i don't know i would be uncomfortable with more than 300 so 300 would kind of be my limit on where i'd be comfortable putting in the system you know to each his own some are going to argue that i should never go higher than two your call what you want to do but that just addresses how much pressure and that's the advantage of a nitrogen tank over compressed air shop air compressors maybe 150 psi max is what you can get in them and with nitrogen you can see i can go a lot higher so advantage again nitrogen still have 100 psi in this i'm going to spray the rest of this down and make sure i have no other leaks and the nice thing about it again oil is a guide as we saw down below we had oil residue we used that as a guide for where our leak was but you want to spray hoses fittings we'll pop these straighter valves off here in a minute we'll spray those too make sure our schraders are not leaking over here for my receiver dryer i have some oil on here but that may be from this power steering pump and line i want to make sure we have no leaks on any of the connections any of the ones we can see there's some down there up here at the at the evap core like where it goes into the dash and spray those down just using car wash 50 50 mix of car wash soap and water is all i'm using these valves are closed i want to open these up this is going to take the schrader inside and it closes it i'll do the same thing here i still have 100 psi in my system and i want to spray these guys service ports is an area where a lot of people forget to check because you have your gauges on there you'll never see a leak so we just want to make sure those look good too and they do all right because i don't want that crap in my in my lines just blowing them out put these back on we have a known leak underneath we're going to fix that so at this point i'm comfortable i don't see leaks anywhere else at this point i'm comfortable just draining this off there's a check valve in the end of this hose so you guys are going to see that whenever we start charging this check valve we're going to utilize that so when i open this it's going to put the refrigerant from the red line into the yellow if i open the blue it puts refrigerant or whatever's in there blue line to yellow so keep that in mind when you open these valves what you're doing is you're allowing the blue to attach to the yellow when you open this one when you open the red you're allowing the red to attach to the yellow there is a check valve here again so what i need to do to drain this system take the hose off here and then i can open either the blue or red and we're just draining that nitrogen out of that system and then i need to get some tools underneath one of the things i learned about these old nissans from back in the day if you have a 10 millimeter a 12 millimeter and a 14 millimeter wrench you could take apart this entire car it's 10 millimeter you should get a shot of the of the power wagon man we we uh i'd like to say i'm done with it a truck like this you're never done with i'm gonna make it oh stop what are the chances that this ah sweet now this was a florida car if this was a pennsylvania car that might never come loose that is a cardinal you're hearing that's a you do this every time we film out here i'm learning my birds as i get older i enjoy those things as a young man i never cared just dropped it there she is look at that old flattened o-ring look at that thing they don't get much worse than that that's supposed to be a regular o-ring it doesn't look anything like it does it yeah i need some o-rings oh there's a blue one that's our guy right there that actually was blue at one point in time that's the one i'm gonna try he said it was blue it is blue oh yeah you can kind of see it that's black that's blue sweet i'm gonna lube this o-ring too a little bit of ester oil again do your research on your oil folks this stuff is water soluble too so you don't want to leave it exposed i don't maybe water soluble is not the right word it will absorb moisture i make sure i don't have two o-rings here i gotta feel for it okay sorry i can't get you guys a shot of this so there's really no groove there at all for this o-ring just sits along the collar oh yeah what it fits perfectly we're gonna re-air we're gonna re-nitrogen charge it anyway okay center hose let's reattach this close these valves depress the schraders back to our nitrogen tank with our safety with our safety tires oh we should sell those okay we're just going to go 100 psi again i could probably go less but i want to make sure watching the low side oh a little higher than i expected so that's like you get an exact number like 103 and a half what do you think it's not quite 104. who's your daddy who's your daddy jake jake's my son who owns this car that looks good son i like it all right since we know that our leak that we found is fixed this decay test we're going to do where we're going to walk away from it for like 15 minutes we just want to make sure that gauge doesn't drop at all and that is just a hair above 103 from my angle we'll come back in 15. all right so it's been like a half an hour that gauge is exactly where it was when we left off i like that a lot what i was going to introduce to you guys today is another way to do a final leak check and that's with a micron gauge and unfortunately for us i have a dead 9 volt battery for my micron gauge so i can't show it to you that's okay i've done hundreds if not thousands of ac repairs without a micron gauge i realize that this is a nifty tool and i wanted to show it to you guys it's able to read vacuum levels much more sensitive than our gauges and if you can pull down to a certain level that just ensures you have no leaks and that's the advantage of this tool next time i'll show it to you for us we're going to do it the regular way first one it passed was the pressure test so i'm going to bleed this out that's just nitrogen we're bleeding out no harm to the atmosphere of course our atmosphere is what 70 some percent nitrogen as it is all right now what we're gonna do is we're gonna pull this under a vacuum i got a vacuum pump right here this is another inexpensive component you can get one of these for 100 bucks 135 maybe i paid for this one back up here you see we're already pulling into a vacuum watch your low pressure gauge i'll have leave both of these open you really don't have to have them both open but watch your low pressure gauge we want to pull very very near 30. again this is the advantage of the micron gauges you get a micron gauge in series with this blue line or the red line really doesn't matter and measure your system and uh it can really indicate much better than this can as far as no leaks go but we'll let this pull under for i don't know this thing was exposed to atmospheric pressure for a long time i'm sure so we're going to let this vacuum pump go for at least a half an hour and then we're going to come back take a look at these numbers we'll do a final decay test and we can kind of do that now before we turn the walk away let's close these valves [Music] and we want to watch this gauge here and make sure we don't see a climb on that gauge if you immediately see a climb with these closed and that means there's a leak in the system or there's still uh moisture boiling off too but that looks pretty good so we'll let that go and again we're going to come back in about a half an hour or so and the point of pulling a system under a vacuum like we're doing is we're pulling all of the moisture out of the system and this oil will absorb moisture too and so we want to make sure that we pull into a deep vacuum which is going to pull all that moisture out of the system it boils it off [Music] water actually boils at i don't know the numbers offhand but very very low low temperatures under high vacuum so we used to play around in the classroom and take a mason jar full of water and put a vacuum hose on top of it turn the vacuum pump on you can actually watch the water boil at room temperature so that's what pulling a vacuum on the system does as with building pressure over top of a liquid raises its boiling point pulling pressure away lowers its boiling point that's what we're doing here all right while we were waiting i was playing around with my micron gauge and i found another battery and i do have it working so get a shot of this first uh what i'm doing right now is i have both these closed i'm not pulling on the system so the vacuum's kind of trapped right here and i'm just measuring what the uh vacuum pump itself can pull down to and i'm showing 520 microns and i don't think that's very good i think that this pump is not all that great i i think from what i was reading 500 is what you want to at least be able to pull down to all right i know i had 520 here let's see what we can pull on this system i'll attach it here i had all of those closed [Music] open that [Music] pull a vacuum on this system i think this is a a worthy tool to have if you do a lot of ac work if you talk to anyone that does hvac work for a living they won't repair systems without a micron gauge that's your that's your guy to tell you you have no leaks in the system because back in the day we didn't have these micro gauges uh one of the things about them or what we were taught is and actually we've all seen it we i've seen systems hold vacuum and not seal under pressure okay but the problem with that in that that mentality in that whole process is you're talking about a vacuum gauge with really really wide margins for measurements and you can't see those small numbers and so when you're talking about a micron gauge um i don't think that that would ever happen like we used to miss leaks using vacuum pressure was the key and i'm comfortable with this system and what i saw with it holding pressure for that amount of time but i guess what i'm getting at is this is another way that we can verify that we have no leaks in a system is if you if you can pull down to a certain level and i'll get you guys a number here in a minute uh if you can pull down to a certain level in your system then you shut it off and you look for a decay uh with a micron gauge it's going to ensure no leaks and it's just this is new to me first time i've ever done it and um i'm sure there are variables your pump is is going to be a limitation too in using this tool i believe but this is absolutely one where a decay test i can do better get a more zoomed out shot i want to show everyone i'm closing these valves now we're going to do a quick decay test i know i'm only down to 5 30. i'd like to see 520 what i saw here but valves are closed i have nothing else pulling on the system even though you hear the vacuum pump running in the background in fact i'll shut it off and you talk about a decay test one that you can see accurately it would definitely be that you walk away from it for x amount of time come back and take a look at it micron gauge first time using one so be looking forward to your comments in this one as far as usage what you guys are using what kind of numbers you want to see what are your variables i'm at 520 i have 20. it's 520 good i'm down to 510. all right at this point we wait now caleb i wanted to at least show the micro engage we'll talk about it a little bit more i'm gonna let this vacuum pump run for a half an hour like i said we'll come back i'll get you some better numbers on this micron gauge um there is something i forgot to do and we don't want to continue pulling a vacuum on this and then add the oil later i want to put the oil in so i said i was going to put two ounces in this using the ester oil and i have a milliliter beaker here so it's like 59 milliliters is 2 ounces so we're going to put we're going to put two ounces in this and uh this system holds five ounces of oil um when it's empty just an fyi okay let's turn this pump back on and what i'm going to do is i'm going to pull it in through the high side i can do it on either one but i don't want it getting into my micron gauge so we're gonna go we're gonna pull on the system from the from the low side this is still pulling and then open this and i'm gonna suck this in [Music] cool and we're getting all that atmospheric air back in the system as you can hear i'm going to leave this closed because i don't want any of that oil being pulled back out so we'll just pull from the low side now only so um what we're looking for is really under a thousand what most of the guys using this micron gauge so zero to a thousand they're saying is a clean leak free system uh one thousand to two thousand we got moisture present above 2000 we have an atmospheric leak and so those are just some numbers we were able to pull down to like 5 10 and watch that pull down some more here again it's a tool that's available to us i think it helps like i said i've been doing this for many many years without a micron gauge but that doesn't mean that this gauge can't help us in the future um something else as we're watching this pull back under is this has been a retrofitted system and charge capacity is 32 to 38 ounces so we'll just call it 36 for easy math with the cans because they're 12 ounce cans if we were putting r12 in this we'd use three 12 ounce cans but r134a is a different molecule and so there's a conversion um the the conversion is i found this on the internet the formula would be r r 12 charge um times .9 minus 0.25 pounds and so as an example um we'll call this a two pound system because i said 36 ounces is how we're going to charge it said 32 to 38 we'll go 36 which is exactly two pounds so two pounds times .9 minus .25 would be 1.55 pounds and um the conversion for that for ounces is 1.55 pounds is 24.8 ounces so what we're going to do is we're only going to put two cans of r134a in this as opposed to what the specs said which is three if we were using r12 that's the plan we'll see what kind of pressures we have when we're done but that is the plan all right we'll come back to this we'll let this pull all the way down that i pumped a whole bunch of atmospheric air in there that's why it's taking some time to come down we'll come back to you guys in a half an hour once again um after putting oil in this we pumped all kind of air in the system so um we don't want to just let that go like you don't want to do the oil edition the way i added it you don't want to add that after you pull a vacuum on the system because you're pulling air back in it so we got to wait another half hour all right we're back i just shut the compressor off and i closed these valves and take a look at our micro engage we're sitting at 500 microns so that's even lower than i could get it when i tested it on my compressor i'm sure if i would let it run longer i could have got 500 but i'm gonna say 500 is as low as that compressor or vacuum pump is going to give me i keep calling it a compressor i'm sorry about that but we're just doing a final decay test right now so i'm anxious to hear your guys thoughts on the micron gauge and what you think of that number again 500 510 520 that's the most i could get from that compressor itself when i was just on the yellow hose so i'm absolutely comfortable with this number regardless um again the material i was reading uh many many of them comments said 500 microns is what you're looking for and this is a real nice decay test too so i got hot water sitting here we're gonna charge using that with the cans and i need to put a straighter valve in here all right so that's my timer from when i shut this off and take a look at the micron gauge it's at 510 and i believe that 510 to 500 it was kind of hovering right around that that range i'm going to give it five more and we're going to watch it i want to make sure that that's not climbing there is a check valve on the end of this yellow hose so keep that in mind as we're charging that uh i'm going to utilize this check valve for me in fact me putting this additional schrader in here wasn't really necessary can tap heard a little bit of flow there it looks like we filled this yellow hose it's okay i'm not going to start charging i want to watch that micron gauge so caleb just asked me did that go up by 10 and i said yes however this goes in 10 increments so it's either going to be 500 or 510 so we were five minutes in when it went from 500 to 510 we're now eight and a half minutes in it's still sitting at 5 10. so we'll go till 10 minutes and i'm gonna call that good now of course you can you can do leak checks for a much longer period of time and there are decay tests you can do with this micron gauge and again you guys that are following this video read the comments there's some smart people in here that are gonna give you some good guidance on using this micron gauge probably better than what i did and let's get a stopwatch here i'm 11 i'm 11 minutes in and i did jump up again it's now at 5 20. so what's acceptable what's not how much of that increase right there is from my newts my new my newts my newt amount of moisture still boiling off in the system and i'm looking at vacuum levels i've never seen before so these are some of the variables you're you're allowed some rise here there are variables with this and this is where the comments are going to come in i am comfortable with this it didn't fail the pressure test when we were done that's my most important thing for me as far as these micron uh increases go you guys i'll let you guys be the judge i'm comfortable with that but there's something else i'm not comfortable with take a look at my gauge setup and i don't know enough about this this tool i don't want to add refrigerant i always like to add to the low side of course with it running you never add to the high side you only add to the low i do have the ability to charge this system with the high side with it off using hot water but i don't want this micro engage in here anymore and my issue there is exposing this to moisture and i don't want to do that so um we're going to stop with the decay test i am let's see how many minutes in we are 12 minutes and 41 seconds in [Applause] i'm good with that i'm taking this off so i'm gonna close this valve to isolate this and then i don't have a check valve in the end of this i'm going to close that one's already closed um i want to reattach this to here without really exposing much much atmospheric moisture and this this isn't ideal but i'm going to do it just stay there i am being a little picky here guys as far as what i'm doing and why just want to make sure i'm giving you guys good information that's all so i don't have a check valve here i just made a check valve so we're going to take that off of there i'm wondering if i set this up differently next time i can avoid this okay so i didn't expose the system to any more atmospheric air but i'm wondering if i would have set this up now thinking about this yeah i should have put i should have put the micron gauge here and then the blue hose here ouch should have done it that way because then what i could have done is simply unscrewed the micron gauge and there's a check valve there that's the way i should have done it and then i could have left this in the rest of the time oh well live and learn all right so my schrader valves are still depressed i can add to either side of the system with the engine off in fact we could blow some in this high side line just to clear out the oil i want to do that first because i added oil to here and so let me uh just kind of open this up and we'll open the high side port you see the liquid flowing in the sight glass you'll see low side pressures climbing and i'm adding that as a liquid i'm just kind of flushing that oil out of this red hose and down into the system that's the discharge of the compressor too and then once you hit pressures that are equal outside so it's like 90 degrees outside and roughly 90 psi that pressure temperature relationship it once we get 90 in the system it's not really going to flow anymore in and so that's the purpose of the hot water so you just dunk your tank dunk that in the hot water and watch your pressure up here so that can it didn't really rise anymore that can is pretty much empty we'll let that go for a minute i'm going to close my high side service port really important i'm going to start this now i'm going to add the rest of this to the low side we do not want to add to the high side with the compressor running and then just because i put oil in here manually i'm just going to turn the compressor face by by hand to just push any thing out of that compressor should it happen to be in there um just being overly cautious but when you put a new compressor in you want to do that too some new compressors will come with oil inside of them and you don't want to overcharge the system either which is a common mistake remember your system has oil all through it some of these compressors when you replace them will have a full system charge of oil in there yeah you don't want to you don't want to use that you want to dump all that oil out and maybe only add an ounce to a compressor replacement if that's all you're changing all right but we're good i'm going to start this valves are shut that cans open but these valves are closed so nothing else is going to flow in here we'll be able to watch those pressure readings as soon as i started that compressor should turn on [Music] [Applause] did it turn on sweet all right let's continue adding on the low side keeping in mind i'm adding right here which is this the suction line so we want to be careful that we don't dump liquid into here [Music] so with the can this is empty now i'm i'm basing that off of pressures here you can watch my low side pressures like there's nothing else there's a little bit left in that can but if you add with the can straight up and down you're adding as a vapor if you add this way you're adding as a liquid and when you're adding to the compressor with it running when you have a low side service port that's that close to the compressor you can put liquid refrigerant in the compressor and ruin the compressor so just be careful with what you're doing on that front okay we do have six feet of yellow hose six feet of blue hose by the time it gets there we can argue that that is gonna be a vapor anyway you just wanna be careful with what you're doing the only reason i'm shaking the can is to feel the liquid level that's left in it for no other reason you'll see you'll see people charging ac systems and they're sitting there shaking the hand the can the whole time totally not necessary only reason i shake them so i can feel the charge level all right so that can is empty i'm not going to be able to get any more than than that 30 psi out of there so we're going to hear a little hiss at the end never add to the high side again this one's open we'll close this don't really have to i have check valves here take this off of here a little bit of hissing coming out of the can just some vapor at the very end nothing you can do about that you cannot get all of it out we're going two cans again utilizing check valves at the end of this i'm not flooding this hose with atmospheric air because i have check valves here or did i i just did so so think about this i have a check valve that's depressed here i remember this now and why i didn't want to that was dumb so i put a check valve in the end of this thinking oh yeah i'm gonna be good because i have a check valve there now no when i have this in here i what i did as soon as i took the can off is i flooded this yellow hose with atmospheric pressure so it was good that i shut this off and so that's that's going to need to be purged so i'm going to show you how to do that and we'll do that differently next time i should have taken it off of here that was just dumb on my part all right so you got a hose that's full of air what do you got to do you got to purge it and to purge this line we'll go liquid these are closed watch up here just real quick there you go line's purged of air okay now is that legal to do i don't know sometimes you have to do it you know you can't prevent all refrigerant from going to the atmosphere that's how you purge a line without a vacuum pump i'm not going to pull a vacuum back on that line just so i can hook it up to another can no that's how you purge a line all right adding back to the low side with it running being aware of my liquid vapor scenario open this up and we'll keep an eye on our high side gauge as we're watching the low side and i really brought the hot water i guess i really don't need it since i'm now adding with it running i was planning on adding with it not running which i can do let's stop this for a second and i'll do that so i shut this valve still got a bunch of liquid in here you're going to reach a point again of pressure equalization where you can't add any more once the pressure in the system equals the can and that's what the hot water is for so we can now go as a liquid too adding as a liquid look at my gauge up here watch see the refrigerant flowing in so that's how you can add to a system that has 125 psi arrest pressure in it right now because i got hot water and i'm heating the refrigerant and it's it's really a much safer way to do it when you have a line as close to the compressor as we do like this so variable methods many different methods not cans just about empty so i'm going to close that off for a minute start this back up [Music] raise our rpm a little bit judging by my high side pressures being at 225 and climbing almost 250 now i definitely don't want to put any more refrigerant refrigerant in i think the two cans was the right call the 24 ounces i think if i put more in this it would our head pressures would be too high we'll get some uh discharge air temperature readings here in a minute we'll keep watching that what i should have done if i was going to add another can again close this up here first in case you do something wrong and what i should have done is i should have separated it right here so now that check valve is being utilized and then there's a check valve on the end of that now what i can do is take this off and go right to my next can and then that's how i should have done it and i separated it right there so that was my fault get an idle pressure reading there caleb let's get my thermometer and jack it inside this thermometer has seen better days but what we want to see i mean we always wanted to see like 40 degrees of discharge air and um last time i used this gauge it was way off calibration one of you guys called me on it you can calibrate these i was like oh i got to get a new gauge you don't just need to mix ice and water together and then put the thermometer in it and set it for 32. science so you can adjust these so i'm not sure that that's accurate okay i need i need to go get ice and water and calibrate that ice and water this is some science if i've ever seen that yeah i mean it makes sense right i'm showing like that that is 75 degrees clearly it's not i'm gonna move it around for a bit 32. i'm just warming it up with my hand now we're up to about 80 degrees okay put in the bed you know on a day like today i don't think you're going to get 40 degree discharge air but ideally that's what i'm looking for when i do ac work i want to see i want to see a 40 degree discharge air of course your climate is going to matter is it really humid you know it is really humid today and it's really hot it's probably i don't know 85 degrees today and really humid i feel like this one he's got some duct work issues here caleb i want to go in this one he's got he's got better airflow here you want to feel that kind of bite on the back of your hand when you're putting your hand up on the on the vent day like today i'll take 50. i've heard other people say you should get a 30 degree temperature swing from outside air to you know here so if you're in arizona it's 110 degrees you're not going to get 40 degrees of discharge now i'm at 1500 rpm how much we drive this get a little bit more airflow across the condenser we probably get a little bit better numbers here too it looks like 50 dead i think it'll be even cooler when you're driving it too i'm perfectly fine with these numbers this looks great nice easy fix for my son cost me like 50 bucks in material and honestly i have two extra cans so i only use two cans final idol numbers about 28 psi on the low looks like about 210 215 on the high those numbers might be a little bit low i bet you this could use let me go a little bit higher rpm and watch it i bet you this could use a couple more ounces let me see oh that's at a higher rpm i i feel like i feel like i could put like six more ounces in this i'm gonna do it see if we can get that 40 degree number too thought we were done but those numbers are low i was worried about the high side pressure before but it's come down significantly i'm gonna put like i'm gonna charge now based on the on my high side pressures i don't mind like 250 we're under 200 for a day like today again it's gonna vary remember 32 to 38 ounces of r12 is what this system called for and i only put in 24. okay all right we're gonna add this as a vapor just a little bit at a time watching my high side pressure why is that dropping even lower it shouldn't be oh compressor shut off dumbass watch that again but something's not right i want to see those high side pressures come higher and i want to see low side around 30. high side day like today at a higher rpm i mean 250 easy on the high side that looks pretty good right now i feel like maybe we we got a little bit of a txv that's sticking and these numbers to me even though i added about a half a can more these numbers look like we're still low on charge watch my pressures when i raise it low side drops pretty low and the high side's dropping too if we're not pulling enough in to compress it to make the high side higher and i forgot about one piece on this systems that use receiver dryers will often include a sight glass and you can use the sight glass as a guide to charge level there shouldn't be bubbles in the sight glass and it what looked like an under charge to me it's i'm is confirmed by this sight glass i'm gonna keep going with that can in spite of the numbers that i looked up 32 to 38 ounces or it was yeah thirty four yeah thirty two to thirty eight um i'm putting i'm putting the rest of this can in or at least i'm gonna watch this sight glass as i'm adding refrigerant just gonna add to the low side now i'm going to watch my high side pressures i'm still sitting about 200 psi about 210 and we're just gonna go the full 36 ounces of this this third 12 ounce can i put half of it in before see some better pressures than what i was seeing all right let's stop there now i'm at 250 35. still pulling low on that low side side pressure is dropping i'm okay with that i'm gonna keep going and there's only there's only an ounce or two left in there i'm not going to add any more than this can but take a look at the sight glass now as i add the rest of the way uh compressor just disengaged so we got to wait till it re-engages there you go look at that see how clear it is now see how the bubbles are gone 36 ounces was what this needed now what we don't know about this system when it was retrofitted it is possible that that someone replaced this compressor [Music] with a larger compressor i don't know it's possible all right compressors running as you see with the gauges as pressures look pretty good 35 and 250 come over here look at the sight glass one more time it's nice and clear and then let's do a higher rpm test and then we'll do one more test inside so raising my rpm let's watch these gauges that's much better 24 24 and 250. sweet sweet let's go well i'm not going to add any more i'm comfortable with that so the final piece i wanted to show you before i realized we were still under charged is this let me show you let me close these off this cans empty and done we're going to utilize this check valve on the end here step one take your high side service port unwind it which closes the schrader so now you've trapped that 250 psi in this line okay step two open your high side valve there's a check valve here so we're not gonna vent it all that high pressure is gonna go in to the yellow hose it's sitting right here step three open your low side slowly and pull all of that refrigerant in from your red hose and your yellow hose into your low side of your system so watch gauges are dropping we got 30 on the low and 30 on the high and now what we do over here take this and open that straighter open that valve which closes that straighter these are both isolated now and all we have left in the gauges is rest pressure that's it 30 to 40 psi shut your car off you can let this high side dissipate if you want to before you take it off we don't have to that's it and what that did that final step is that kept all of that pressure from maintaining or being in those hoses and you know you're supposed to recover your gauges when you're done you don't want to vent that to the atmosphere and being that i don't have a recovery machine here at my house that allows me to have as little as possible left in the gauges themselves okay put my caps back on we're done under the hood close this up and we'll get back inside for a final temperature measurement i'll pull over so you can get a shot of this thermometer i'm showing i'm showing about 42 to 44 degrees of discharge air on like a really really freaking hot humid day in pittsburgh the third can and a test drive was key i like it that's great that's like almost 40 degrees difference of outside air and those numbers that i gave you guys as far as the conversions go um those aren't my numbers that like 0.9 times the amount minus 0.25 i just googled that i remembered when when we did these it was 10 less we just we just did 10 less when we were charging with r134a from an r12 system i think it was 10. it wasn't significant and i was putting a significant amount less in this at first i was comfortable with it until i saw those pressures as i'm revving it seeing the low side drop and the high side drop i was worried about the expansion valve and uh the sight glass was really really helpful in this case that you know we're able to use the sight glass for bubbles which is another way that you can charge a system just keep going you got one of these systems just keep going until your bubbles are gone make sure the compressor's running of course dude it's freaking freezing in here here get a shot of this now we're like at 40 just above 40. and this v6 has enough torque with the stick that i really don't feel the bog in that compressor these smaller cars when the ac turns on man they can really you know pull the power away from the the car and this feels really good jake's gonna be super happy gets his nissan back with a working ac system sweet so yeah thought we were done a while ago i have the gift of gab there's a reason uh i've been teaching for 20 years and sometimes it's to my detriment and yours but if you made it with me this far again i'll put links in the description of this video for other ac ones that i've done and uh i have i have ones out there guys that are dealing with compressors that aren't kicking on with good charge electrical problems bad clutches uh bad compressors you name it i have them check the description guys thank you so much we'll see you next time all right so as we're sitting here in the air conditioning in my truck and it is it's temperatures it's freaking hot man it is 91 degrees outside with a 75 degree dew point um just wanted to uh talk about my son's car we did yesterday real quick a couple things one is i have to apologize using a tool for the first time live in front of you guys does not always make for the best training video um because i learn things along the way and i see things that are incorrect and and you know that's just the way it goes we film live we don't do anything off camera so you take the good with the bad um but this micro engage what i wanted to talk to you guys about is some things that i learned last night that i didn't know and they're basic things uh you'd think that i would have understood that at the time but i did not and one is is what a micron is i wanted to equate microns to inches of mercury for vacuum measurements and so i did a quick google search and it's one inch of vacuum one inch of mercury is the equivalent of 25 400 microns and that makes sense that's the number i'm used to using is millimeters to inches well there's 25.4 millimeters in an inch and so that number kind of you know goes hand in hand there too so but think about that for a second 25 400 microns in one inch of mercury so why is that tool um so valuable in leak detection think about this for a second as an example if i'm at 29 inches of vacuum or if i'm at 28.9 inches of vacuum i'm never gonna see that on my on my gauge on my conventional manifold gauge set i'm never gonna see that tenth of an inch difference in vacuum so if that vacuum would drop a tenth of an inch i would never see it i can barely see the difference between 28 and 29. so now think about that for a second a tenth of an inch move the decimal one place that's 2 500 microns for a tenth of an inch drop and i was worried about a 20 micron rise during our decay test i hope you guys are following what i'm what i'm saying here that number is so small it's so small if a tenth of an inch of vacuum is the equivalent of 2500 microns right what am i worried about 20 micron rise so the decay test of course we're going to see some increases in microns and they go by tens what's acceptable it's gonna be different probably for every system and everybody's gonna have their own opinion on what's an acceptable decay test for microns the other thing is what is an acceptable number to pull down to i have a friend i spoke to and he told me he uses really anything below 750. um i read some other material that are saying anything under a thousand and we were at 500. something else that you want to do is baseline your com your i keep calling the compressor still to today uh baseline your vacuum pump and see what it can produce and ours was able to pull down to around 500 and so as far as what's acceptable number to pull down to it's going to depend on the system you're working on it's going to depend on the pump that you have so baselining your pump is important too so so that's it i think the micro engage is a very valuable tool in that it may eliminate the need to have to repressurize the system when you're done take my rv for example we did a an evac and recharge on my rv and that's a system that holds like five pounds of refrigerant it's a huge system so for me to re-pressurize that system when i'm done fixing the leak with my nitrogen tank i'm using up a lot more of my nitrogen than i want to micron gauge is going to come into play there you you pull that under a vacuum you're going to see it if you have a leak you're going to see it it's just not going to pull that low and use my tenth of an inch example again that's 2500 microns you're going to know it you're going to see it um i'm still good with the the test that i've done over the years and not using the micro engage i'm just introducing that tool i think it's very valuable again and is is there ever a scenario where we can we can hold um vacuum but not hold pressure um i still think that that is possible but uh be anxious to hear your thoughts on on if the micron gage ever misses it have you ever seen one i've certainly seen systems hold vacuum and not pressure but i don't have a gauge that's that sensitive and that's the point so be curious to hear your thoughts on what you guys have seen on that front um micron gauge is pretty sweet and um sorry for not really knowing what i was doing with that tool yesterday but we just wanted to do this follow-up to uh add some clarification so thanks again guys and and we'll see you next time

Channel: ScannerDanner

Views: 403,090

Keywords: engine performance diagnostics, technician training, auto technician training, rosedale tech, auto repair, ASE L1, how-to, DIY auto repair, ScannerDanner Premium, automotive electrical systems, check engine light, diagnostic training, troubleshooting electrical faults, auto mechanics, auto mechanic training, online auto mechanics, A/C repair, micron gauge, A/C leak test

Id: aN-Xni8Sg-4

Length: 76min 13sec (4573 seconds)

Published: Sat Jun 25 2022