I have been a HVAC service tech for 25 yrs the only thing I see is normal we put the straight end of the hose to the manifold and the curved end to the adapter for the service port but it works either way great job over all brother also if u idle the motor up to 1500 RPMS than set it at 42 to 44 and it should be good cause going down the road the engine is at 1500 RPMS and air moving across the condenser coil so always idle the motor up to 1500 then set the charge cause those pressures are for 1500 RPMS they will be lower at idle that’s why they look low
Can you fill an AC system using the gauges instead of using the specified quantity of R134 under the hood?? Is he saying it doesn't matter if you disregard the specified quantity? Cause I got a car that isn't blowing super cold, but the system is sealed still after 20 years, and I was gonna evacuate the system before filling it so that way the quanitty is correct... But based on this guy's logic I can just see what the gauges are at and add however I see fit as long as the guages are in spec.
@@kmlumd44it’s better to fill it with the amount labeled on the car. Using the pressure chart isn’t the best way to do it. Evacuate the refrigerant and see how much is weighs for science. Then fill it back to the right amount labeled in the hood of your car
You were soooo close! Your pressures are good, which is why it is cold air when driving around. Hook your gauges back up like you did, then raise your RPM's to 2000-2500, and watch your pressures while doing that. You'll sleep better knowing your pressures now maych the chart. They'll drop back down when your rpm's.go down.
Why did he need two cans if it didn't change that much pressure wise ? When do you open high side valve . I don't think I saw him open it. When do you open yellow side valve
@@connorwallace9643 You normally don't open your high side on MVAC , you just use the gauge for problem solving. As far as where your pressures should be you can look it up online and all it tells you is the weight from the factory and if your using a 30lb tank and scales you can just drop that weight in HOWEVER if I have to use small cans I normally go by Ambiant temp 82 to 90 outside and my temp gauge in the vent should be at a idling vehicle 39 to 44 is what I like but you will see some systems at 48 50 and it be 95 to 100 outside. Once I get pressure where I want per temp, I drive the car around while looking at the temp gauge. Long as temp is stable its good. Go by these steps and your good. Hés correct about a vacuum but you can vac it down normally 10 to 12 min then add freon, if you have a leak , pull your high side service valve out and using an injector add your oil and dye, reinstall with new service port valve-replace low side to, pull vac only on low side this is so you don't suck all you dye out, vac 12 min, dump freon in. I know long comment, but i love doing this stuff, I got license through MACS and opened up my side business at my house. I have been doing this for years and I have learned a lot My first 3 years I had a 40 year vet I could ask question to. Been on my own 5
As an air conditioning mechanic, I think you did a really good job. I don't know what laws are in the united states, so bear with me. In Canada, you need a license to purchase real refrigerant. The stuff we can buy at a parts store, isn't "real" r134a, but a hydrocarbon cocktail (propane, isobutane, etc.) that works in r134a systems. The catch, is that the weight of the charge and system pressures are very different. The products I'm familiar with require only 40% of the systems listed weight. This leads a lot of people to overcharge their systems, which prevents the ac from cooling at all. Its actually better to under charge than to overcharge. Pressure is great for diagnosing issues, but not great for charging.
@@1RoadGarageyou didn't show and open only the low pressure, blue doo. You didn't open the valve on the gauge red one, high pressure. Why you didn't do that?
Lol, you will know if you overcharged it. You will find oil from that AC system leaking from your AC line seals/o-rings. Then you will need to go have the system serviced lol.
I sometimes get myself in trouble when I criticize UA-cam posters, pointing out mistakes and things that they left out? But you need not worry, because your video is the most complete AC recharging video I have watched in the past few days! You showed all the steps. Please take this compliment, as I don't give very many!
That was very noble of you. However, this is the one time you should've opened your mouth. Instead you let this youtuber get away with doing a completely wrong ac recharge. As you know, the ac is a closed system, meaning the amount of refrigerant in the system is what will be there indefinitely unless there's a leak. A low charge in the system after having no issues means exactly that. The first would've been to evacuate the system and pull a vacuum on the system. Since it's obvious there is a leak, the next step is to find it. My method would be to let the system pull in about 50 psi of r152a and then spray soapy water on each connection point. Once the leak is fixed then vacuum system down again, more r152a, then recheck. If no more leaks, then a final vacuum for about 45 mins to be sure all moisture is out of system, and then recharge with your refrigerant of choice ( just make sure it's compatible with the oil in the system). *mic drop*
Just a tip. Turn off the recirculation system on your a/c when charging, allowing only outside air to flow through the evaporator, which will give you the true pressure readings on your manifold gauges.
Since the compressor speed varies with vehicle speed unlike home hvac, it’s reasonable to assume the pressures increase while driving. This makes it kind of Kentucky windage to get the proper AVERAGE amount of refrigerant in the system for all ambient temps and speeds, without over or underfilling it just sitting static in the driveway. The thermometer in the vent becomes the most valuble indicator
Turn off the recirculation system on your a/c this is the right way to do it you need to use the outside air temperature to add the correct amount unless you recover and recharge by weight!
Many have said this, normally what I do is purge my high side while the engine is off by cracking the red knob just a tiny bit then closing it. You leave the yellow hose disconnected. then i repeat with the process with the low side with the engine on. Then do what your purge process. During the recharge, i use a thermometer to measure the temp on the condenser near the inlet side and compare it to the temp on the high side gage. Try to get the temp on the guage to match the temp at the condenser inlet without going over. Once these are close, usually within 10 to 15 degrees, your system is full. You will note the suction line on your compressor should be condensating. This means there is cool liquid refrigerant making its way back to the compressor to help keep it cool and lubricated. Its always worked for me and kept me cool in the Florida heat. Charge volume specs never actually tune your ac system because each system is different, and it's volume capacity depends on not only manufacturing accuracy but also elevation and ambient barometric pressure. Hence a system charged in denver would need slightly less freon than a system charged in New Orleans. Always go by condenser temp to prevent overcharging.
@@carltonshore8843 not completely, if the refrigerant is completely vaporized, you drop cooling capacity. Vaporization is dependent on temperature. If the lines aren't sweating and back to the compressor, you don't have enough refrigerant
Great video and info bro!! Hey the only thing that I would like to add is when you screw the fittings down onto your AC lines don’t screw them down all the way because they are known to break the Schrader valve that’s in your AC line so basically screw it down until you see the gauge move and maybe just a little bit turn past that and that should be good. Hope this helps.👍💯
If you follow this video, it shows how to introduce non-condensables into a system. Yes, air in the hoses at 0 PSI is air at 1 ATM pressure. In the USA, to work on automotive AC systems, an EPA 609 certificate is required. Purged the refrigerant line, but not the high and low side lines. One out of 3. OK. To vent much less refrigerant to the atmosphere, opening the can valve, then closing it will squeeze the air and partially replace it in the hose, then with the can valve closed, purge at the manifold. The refrigerant in the line then expands and expels the air. No need for inverting the can for this step. Gas pressure alone is enough to purge the line. Same applies to the vehicle lines. Open the high and low side connector valves and close them, then release the pressure at the manifold. The expanding refrigerant will purge the hoses. Do this with the engine off, so the low side has more than 15 PSI to compress the air in the hose, then expell the air as the refrigerant expands as the pressure in the hose is released. Keep air out of the car AC system. It can't turn into a liquid and thus reduces efficiency and capacity. Save the environment by venting as little refrigerant as possible. Don't flow refrigerant to the atmosphere by venting it as shown in this video. Might take a look to see where the sight glass is on the vehicle AC system. Learn how to use the sight glass in addition to your gauges for charging. Remember, if you have non-condensable gas in your system, the sight glass will always have bubbles. Only a system without air in it will be able to fully condense the refrigerant into liquid to be seen as no bubble liquid in the sight glass.
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I understand that the refrigerant must be charged through the low pressure line in gas form and through the high pressure line in liquid form. It is not good to charge liquid through the low pressure line. Is that so?
@ You can charge through the high side, but only after the system has been repaired and under vacuum. Liquid can be charged by weight into the high side. If you try to put liquid or gas into the high side, the tank being lower pressure will pump out the refrigerant into the tank possibly over filling it and making an explosion hazard. Some refrigerants are required to be added as a liquid, as blended refrigerants can be distilled by boiling off the higher vapor component first, which destroys the refrigerant glide. Look up blended refrigerants for more info.
@isettech Reference ”In the USA, to work on automotive AC systems, an EPA 609 certificate is required” That statement is true ONLY IF you are being compensated ($ or bartering). “Any person who repairs or services a motor vehicle air conditioning (MVAC) system for consideration (payment or bartering) must be properly trained and certified under section 609 of the Clean Air Act by an EPA-approved program.”
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@@CWK090 This is one of the many things that make me happy to live in the developing world, definitely the "free" world is not free at all, everything regulated, everything normed, everything limited, everything controlled.
Your video helped me fix my kids AC! Now I have some tools, knowledge, and experience to tackle future AC problems on any car. All due to you!!! Thank you very much for your *entertainment* vid!!!
if you were 24 ounces low on refrigerant then you have a leak somewhere. I would like to have seen you take it down to vacuum, say, 500-540 microns, and let it hold there to watch any decay in pressure over about 15 minutes time. Then you could have just recharged it to factory charge. Other than that, nicely done. I'm happy to see you purged air out of the lines before putting it in the system. So many people forget that step. When I do AC for myself and friends or whomever, I always put a blower fan up to the rad/condenser to simulate some driving. thumbs up!
I just rebuilt my entire ac system l most anyway after recharging twice only to not have ac afterwards. Third time was a charm thang god. Cold ac is a blessing
wow maybe that's what I need to do. I've replaced my evaporator/condenser, compressor and it still struggles to get cold on hot days. It used to freeze us out! The dealership purged and refilled it because they can't figure it out. It got slightly better but still not cold. So maybe a third time will help! I'm thinking that there is some crud in the lines somewhere....
It's nice to see others take on something new to them. My opinion is just run it until it starts blowing warm again, otherwise you're throwing money away! If it's lasted 28 years so far, it'll probably be fine for at least several more years with the top off provided you didn't overcharge the system and hurt the compressor. If it is leaking anywhere, it's probably leaking at the service ports and compressor seals...could try soapy water and see if you get any bubbles to avoid having to add dye, but it's probably not a big deal if it has lasted this long. Just run it until it becomes intolerable before going down the rabbit hole of parts replacement.
I'm about to replace my entire system in my 98 Jeep Grand Cherokee and I bought the gauge setup and I want to do this the right way so I am here learning and this is one of the best videos I have come across so far. I really want to know more about charging a new system and removing the old refrigerant from the old. such a good job on this video thanks brother
Unless you are evacuating a system or drawing a vacuum, you do not need to open the red (high) pressure valve on the manifold set. The gauge readings are irrespective of the manifold valve positions. Gauge dials read with manifold valves open or close. The valves control the flow from the yellow hose to the respective colored valve.
Can’t get much colder than that. Smart to keep it safe like you did. The beauty with these old trucks is they are simple and when they work they don’t need fixed until they break. I’d bet yours will blow cold for years to come unless the compressor fails. Good video!
Well, when it comes to automotive AC systems whether mid 90s or later vehicles, this is no different than my 2012 Jeep or my 2013 daily driver Nissan which the latter was low on refrigerant. Same procedure and now it's more comfortable driving to work in 110°F+ temps here where I live.
I do the same, but like to run a little refrigerant thru the low side line to purge as well. I never open the high side at the manifold, so that is that. If the system is empty, and repairs are done, I evacuate the system with a vacuum pump for an hour, check for leaks, then add refrigerant according to the levels indicated by the manufacturer on labels under the hood, looking for, as you said, pressures to be proper with the ambient air temp, and look for cold air out. Thanks for the vid, you do it right. Cheers!
U did pretty good, accept for a few things. 1. U should purge all the hoses. 2. Chevy typically have a back pressure regulator set for 28 psi. So no matter how much freon U sucked in the back pressure will always b 28 psi. U should always charge an A / C system by weight or temp, not by pressure.
100 percent correct. You can only get the best reading on your gauges at 2500 rpm when the car is stationary. Otherwise you get lower readings at idle.
Came across your video and provided me with directions to proceed. I saved it to refer back to the information. Thanks buddy, from South Texas where we are in 100° F heat dome.
Hey there! Just a quick note to add, and please feel free to correct me if I’m mistaken. It seems like the high and low lines weren’t under vacuum, which means outside air might have been entering your system. Ideally, you’d want to use a vacuum to remove any air from the lines. Once that’s done, make sure to seal them off to prevent any outside air from getting back in. This way, your system stays clean and efficient. Hope this helps!” 😊
Jimmy I liked your video very much you explained all the processes very well.. I just finished working on my 95Chev just about the same system as yours. I only got the inside air temp down about 50* F until I drove it at freeway rpm’s then the temp came down to 45*. I was happy with that. The outside air temp was 98*.🤠
For a DIY, you did great! Only once thing I'd like to add, it's a good practice to turn off your air recirculation switch while charging the A/C at 1200-1500 RPM, as the charging chart temp is normally taken as outside ambient air.
Positioning a shop fan (24",36",Etc. drum type) in front of the grille blowing air into the condenser will simulate A/C performance while going down the road. Watch the gauges and see the pressures drop. While you're at it , it wouldn't hurt to flush the condenser out with a water hose if accessible. From the inside (engine side) out. Not internally flush , but externally.
I just redid mine, and it works better than it ever has. I have a handful of tricks I developed over the 26 years I've owned this truck. I also perfected the coolant mix and radiator swap. Just towed a trailer in 97F Austin heat, full blast AC, never budged off the 180F stat set, other than a flicker after encountering a traffic light. 4700lb trailer. These secrets remain unknown because your host insulted be and canceled some posts. Carry on.
hey no worries mate, as temps go up pressure will also go up, you did a great job, if it goes low again then it is time to look for a leak, if you have to recharge a 2nd time then you should vacuum the system and also add some oil but for now you are solid gold!!!
I am also a DIYer.. on the r134a chart (i.e. 175-210psi on the highside), i rev to 2500rpm to get that highside range.. that would also be safer.. avoid high pressure hose from bursting.. that's just mu process :)
I don't know for sure but I've heard where one must vacuum all the refrigerant out and moisture before adding new refrigerant I've always heard that and to use a scale to measure how much to put back in according to the label under the hood
Stay Coooool! LOL Yes. Many do not use the vacuum like they should. I rent it from the local big boys. There is almost always some moisture in there after the years go on. Also, I'm sure you know, but if you suspect a leak - like your cold no longer cold in a week or so, you can use that fancy multi-legged thingy to push leak dye and UV light around (night better). BTW, save your gauges that come with some of the "rebate" canisters. You can use them on the refill cans, later.
Not a pro here. But I have always only charged gas into the low side. Meaning the valve on the can is up. Tilting the can or putting it up side down will give you liquid. If you want to empty a can. Hang the can upright into a small bucket of hot water. I do the same with 30lb jugs too. Just makes the gas charge a little faster.
I too have a GMC, it too cools better when the pressures are lower than those that a pressure chart says what they aught to be. When the pressures are brought up to the charts specification, the temp rose from around 44-46 to 52 or so. Keep the pressures slightly low for the coldest air. Rf-TN
I think the low side should also be purged before connecting the yellow line to the full can. Should be no need to purge the high side since refrigerant will never be added there.
In a two-phase system i.e. where you have the refrigerant existing as a liquid and a gas at the same time which is what's happening in both the evaporator and condensor when it's working properly, the pressure depends only on the temperature of the heat exchangers. Once there's enough for the proper two-phase cycle to occur, adding more refrigerant won't increase the pressure. All you're doing by adding more is increasing the proportion that in the liquid state. Too much will damage the compressor if liquid enters the compressor inlet from the evaporator or if the condenser is too full and backs up into the compressor outlet. The compressor wants gas only - liquid is bad. This is why there's a specific quantity of refrigerant specified. The only way to know for sure if the correct amount is in the system is to pump it all out with a vacuum pump and then refill it with a measured amount. It's measured by weight, not pressure. The gauges can give you an indication of the system performance, but they cannot tell you how much refrigerant is in the system. There are other potential causes of abberant pressure readings including a worn compressor, bad expansion valve etc.
Charging a properly evacuated system is much much simpler if using the "delta drop" procedure. That is, at 1600 rpm, measuring the input air temperature going into the evaporator coil and the output air temp coming out while charging slowly and intermittently (to stabilize) to get the maximum temperature difference. Thats the ONLY way of accurately determining the exact proper charge. Also the accumulator will be warm about half way down and cold in the upper half. That tells you that theres reserve refrigerant in the system. Youre welcome. 😁😎
Question did you purge the suction and discharge? I noticed you purged the feeder hose but you didn't purge the other ones! Anyways great video... I'm a 29-year service technician from Nashville Tennessee
I’m in middle TN as well. Currently trying to solve a rough idle on my ‘05 Envoy. Check my latest video I just uploaded. Here’s a link to my fuel trims: Live Data From 2005 GMC Envoy! Help Me Diagnose Rough Idle! ua-cam.com/users/shortstTO8Oc_T1k0?feature=share
When the weather got hot this year, my truck (a 2000 Ford F-150), also was not cooling. I found one of the Schrader valves was leaking. So, after replacing the valve, I recharged the system and it started cooling like yours.
Only if they're opened at the manifold. The high pressure side doesn't 'feed' into the system and the high pressure manifold valve didn't have any reason to be opened in this top off scenario. The low side should have been bled by cracking the manifold valve open slightly with the yellow fill hose side disconnected/open to bleed it out, then reclose the manifold valve. Yellow fill is always bled every time you connect a bottle/can.
Very well done. Only thing I'd add is; check to see how much refrigerant a vehicle takes(should be by the weight). You don't want to overcharge a system.
Many AC/Heater Systems the fan blows first through the heater core then through the Evaporator,if the control switch does not shut off the hot engine water going through the heater core this will cause the AC air to be a mix and will be warmer than it should be,check for a electric or vacuum Switch in the hot water system,on semi- trucks I have installed a manual Shut off to stop the hot water in and out of the heater core!!! This brings a big dro in AC vent Temperature!!!❤
Jimmy, could you make a video showing how to replace your coolant on your 95 suburban? I have a 1998 gmt400 truck and am planning on doing this myself soon. I always watch your videos because you are always so thorough and meticulous about everything. I assumed you already would have a video of this but when I checked and you didn’t, I figured I would ask if you’d make one if your coolant needs to be changed. Thanks either way, love the videos, from Jimmy to Jimmy👍👍
The delta T on car AC is 30F, so if it's 100 inside car it will blow 70, there is no fixed ok temp, when cool in car 75F it should blow about 45F. Too much refrigerant will damage compressor. Charge for 30F delta and accumulator canister frosty to touch 70-80% of canister. If system is completely flat you have to fix leak, evacuate it, and recharge correct weight.
Hmmm, after 2. Can still no pressure increase on the low side. Sound like the expansion valve is stuck. This regulate the flow of refrigerant throw the system.
Excellent video... For sure will help a lot people saving money out there. To know a good and honest mechanic shop that you can trust in this days is very hard and its sad to say it. Thank you so much for this great video. May God bless you.
My Vivohome gauges do not have a schrader valve to purge the air before charging. OK I just watched an AC pro purge his air by opening the yellow charge line at the gauge even though he had a Schrader valve on his. So if you don't have that valve, that's another way of doing it. The main thing is don't add the freon until you purge the line of air. Hope this helps others like me. Thanks for posting.
Don't get me wrong though I like your videos I like your style and I like the way you present doing your own mechanicking Air conditioning is always tricky what you doing really well job of explaining and showing what one should do thank you for that
Good point at the end of pointing out if you register 0 psi on guages you need to vac out air and moisture and be sure it holds showing no more leaks. Just had to order vaccuum and freon leak detector to find and fix before attempting refill.
I saw comments from pros that said you did a great diy job and I fully agree! And yes better a little low than high. I usually just check with the thermometer and add until I hit 40 to 45 and the compressor runs constantly in full cool mode. I personally don't like the super cold air blowing on me. I'd rather chill out... Slowly! Later.
You really need to recover all, check for leaks, and vacuum and fill to how much your OE manufacture says to have in it. Just checking by pressure is a great way to overfill your ac system and damage your ac compressor.
I'm finishing a compressor replacement on my 05 t&c today. I thankfully saw before getting into this project that pressure by itself doesn't tell you how much refrigerant needs to go into the system. So I bought a kitchen scale, I 'obtained' a copy of the factory service manual, and figured out exactly how much oil & refrigerant I need to put into my system. So I'll be able to measure the exact ounces coming from the scale into the system and I've got the factory manual which has great info on how exactly to perform the tasks I need to do. Already swapped compressor, seals and o-rings, pulled my vacuum & no leaks. Just need to make a final trip to the parts store cause my stupid can tap was machined improperly and doesn't fit the acme 1/4” connectors like it should. Hopefully I can pull this off and get this AC working strong before a thousand mile move!
Probably a pretty good guess on how much to add for you. Mine was completely open, so I had to grab new O-rings and vacuum test the system. I refilled by weight. I am going to pressure test this weekend again, mostly to verify it's the relay that went bad. (I can't just swap out a $10 relay in my car. It's a whole control module.)
Just for your edification, you can buy adapters to go on a 1234 system, because 134 will work in that system. When you get to about 11% of 134 in a 1234 system, you remove the fire hazard that the 1234 carries. It was well-known in Europe for causing engine fires quite frequently when they first started converting over to it. The other problem is is that the reason we use 134 is because it doesn't damage the ozone layer but they still can't explain why they're forcing us to convert over to yet another design except that the 134 patent has now expired. Just like R12 did a couple of decades ago. Many vehicles actually required elope side pressure to be somewhere around 30 to 35. The greater differential between the low-pressure and high-pressure which is usually around 275, the colder the air will be after it goes through the evaporator.
@GlennHamblin r-12 worked great but killed the ozone bad. 134 works pretty well with way less side effects to the ozone. Why they released 1234 I have no idea
When adding refrigerant, never add liquid (high) though the gas ( low) side. The refrigerant instructions state tipping the can, however that introduces liquid into the gas side of the system, that’s how internal restrictions are created. Only top off with gas. It will take longer but ,, that’s the correct/ safest way to top off refrigerant . Many garages/ DIYrs will do it incorrectly to save time ( at the moment) or ignorance. When the system efficiency drops, it will take much more time and parts to correct the previous errors.
In america Vacuuming ac systems Standards are 10 minutes at 20 Inches Of Mercury to Boil off any water in the system if it passes 10 minutes no need to continue if it dosent then you need to do a 30 to 40 minute Vacuum Jimmy @1Road
You done right. Any automotive AC does better driving. The compressor rpms circulate the freon better. I probably wouldn't add anymore. Who's to say how accurate the guages are?
The straight end of hosed connect to the gauge set. There is a label on your vehicle under the hood that tells the amount of refrigerant your vehicle can hold. Sometimes it is less than the 24 ounces you added to your vehicle. So you may or may not be ok depending on your vehicle.
I would also check your fan. I believe this is a fan clutch vehicle and it's likely weak / needs to be replaced. That'll definitely help with your sitting still pressures
Was just about close the video out just before your said “ if your system has no pressure ……” & guess what, I went outside to check the pressure amd there is none on high side and low side. Looks like I gotta find the leak. Appreciate the video
Hello, very good review!. But can you please enlighten me. You purge the air present in the filling pipe (yellow), but there is air present in the low pressure pipe (blue)?, is there a way to purge?, example air conditioning stopped, slightly open the blue wheel, to let out a little air and old freon through the yellow pipe and quickly close, then do the yellow as you showed in the video?. Thank you in advance
I'm just learning how to properly charge auto A/C systems with a proper set of manifold gauges so I've been watching a lot of videos. I noticed that some pros read the pressures when the engine is revved up to 1,500 to 2,500 rpms. I wonder if that's why your readings are low.
HI, for sake of argument , lets say your system takes 34oz of refrigerant...it will work better(believe it or not) with 31-32oz. Also wash your condenser rad with a garden hose it will help for better results. thanks for the vid, be well !
7:15 Didn't purge the high and low pressure hoses. I charge according to the high side. If the low side is way off, you likely have a restriction. My car was last charged by a pro (I used to be, still universal refrigerant certified) to the weight specified by the manufacturer. It wasn't super cold so I checked it myself and it was 15psi low on the high side. Brought high up 15 psi and I can blow 42 degree air at 115 outside. 36 at 100. When it can get really hot like 110+ outside, you want to make sure you are at the low end of the range when charging at lower outside temps. In regards to yours at 80, I'd add maybe another 10 psi high, but I wouldn't open a new can for that little change. But remember what I said about temp, it can get over 120 here and high side can skyrocket at that temp while stopped at a light so restraint needs to be used when charging.
Look at your gauges again carefully there is differant scales for different refrigerants listed on bottom sbove needle stop pin. The manifold reads 3 differnt types refrigerants. I believe your eyes are focused on the outter black numbers on gauge.
You can do this without having to drive around. Just put a high output fan in front of your radiator to blow air through your system just as if you were driving around. If you dont have enough airflow through your condenser, the system will not operate properly. The fan on your engine will not pull enough air through the condenser at an idle. Especially if you have electric fans.
Thanks for posting, like you I was going to try this, but all the pros keep saying you have to evacuate completely and then put in the exact amount for the perfect amount. How you looking?
Working properly on these vehicles, rear air has very little effect. My high side pressures rise 15 psi and my low side about 3-5 if I turn the rear blower on high in my 97 Express van. If the rear TXV hangs open, the system will not cool well though.
And the normal Air that is in this non purged red and blue hoses, are you pumping this air into your A/C and contaminate it ? Or do you purge the air out of this red and blue hoses first before you open the circuit , because you want to 100% avoid any air that goes in your system even if it is a tiny small amount .
Your pressure could be low because you have a leak. Did you verify that by recovering and measuring the amount of refrigerant removed minus the system capacity? Vacuum test? Where did you lose it? Otherwise what you put in will leak out. If you open the system once you find the leak and fix it, consider replacing the dryer.
So if you look at your low press gauge Blue when you are looking at the pressures, you should also look at the corresponding temp scale for R134 on the gauge face. Many over look the it since the print is small, but its the temp that really matters. If pressure goes up the temp goes up. Also, blue is low pressure/evaporator inside the car cabin.......red is high pressure/condenser in the grill of the car. Evaporator should be cold absorbing heat and the condenser should be hot rejecting heat. The law of thermodynamics is heat flows from hot to cold, absorbing heat in the car cabin and rejecting heat at the condenser near the radiator.
It would have been good to first to pull a vacuum on the system to make sure it doesn't have any leaks. The fact that you had to add 2 can of R132 A tells me that you do have a leak and your fix is temporary. All in all good video , this is how we all learn. O'Reillys Auto here in Bozeman will lend the gauge set and vacuum pump to make testing and recharging with very little cost
pulling a vac on the system would require dumping all of the 134 out of the system, without a recovery device this is a bad idea. It looks like a GM that's a couple decades old. A leak detector is a better idea
When I charge AC I generally look for the high side to be about eight times whatever the low side is. When that happens cold air will come out of the vents. My high side pressure are always higher than your chart
Good video, wondering if compressor is going bad with the low pressures? It’s working is what matters, I added 12 ounces to my Toyota Camry and working fine
1ROAD, question: If all I'm doing is wanting to top off my system, and there's already refrigerant in my accord, if I do your process, I wouldn't need to add the entire amount of ounces To my system right?? Would this be just adding in any that I may be low on??
I have been a HVAC service tech for 25 yrs the only thing I see is normal we put the straight end of the hose to the manifold and the curved end to the adapter for the service port but it works either way great job over all brother also if u idle the motor up to 1500 RPMS than set it at 42 to 44 and it should be good cause going down the road the engine is at 1500 RPMS and air moving across the condenser coil so always idle the motor up to 1500 then set the charge cause those pressures are for 1500 RPMS they will be lower at idle that’s why they look low
Can you fill an AC system using the gauges instead of using the specified quantity of R134 under the hood?? Is he saying it doesn't matter if you disregard the specified quantity?
Cause I got a car that isn't blowing super cold, but the system is sealed still after 20 years, and I was gonna evacuate the system before filling it so that way the quanitty is correct... But based on this guy's logic I can just see what the gauges are at and add however I see fit as long as the guages are in spec.
@@kmlumd44it’s better to fill it with the amount labeled on the car. Using the pressure chart isn’t the best way to do it. Evacuate the refrigerant and see how much is weighs for science. Then fill it back to the right amount labeled in the hood of your car
Oddly, the instructions showed the hoses installed backward. Easy to flip if your underhood space warrants it
Thanks for this info. I started to worry because I thought I had been putting it in backwards for the last 15yr.
You were soooo close! Your pressures are good, which is why it is cold air when driving around. Hook your gauges back up like you did, then raise your RPM's to 2000-2500, and watch your pressures while doing that. You'll sleep better knowing your pressures now maych the chart. They'll drop back down when your rpm's.go down.
Thank you!
@@raularteagagavia2835 the wheel as your AC system cycles on and off it’s supposed to.
Why did he need two cans if it didn't change that much pressure wise ? When do you open high side valve . I don't think I saw him open it. When do you open yellow side valve
@@connorwallace9643 You normally don't open your high side on MVAC , you just use the gauge for problem solving. As far as where your pressures should be you can look it up online and all it tells you is the weight from the factory and if your using a 30lb tank and scales you can just drop that weight in HOWEVER if I have to use small cans I normally go by Ambiant temp 82 to 90 outside and my temp gauge in the vent should be at a idling vehicle 39 to 44 is what I like but you will see some systems at 48 50 and it be 95 to 100 outside. Once I get pressure where I want per temp, I drive the car around while looking at the temp gauge. Long as temp is stable its good. Go by these steps and your good.
Hés correct about a vacuum but you can vac it down normally 10 to 12 min then add freon, if you have a leak , pull your high side service valve out and using an injector add your oil and dye, reinstall with new service port valve-replace low side to, pull vac only on low side this is so you don't suck all you dye out, vac 12 min, dump freon in.
I know long comment, but i love doing this stuff, I got license through MACS and opened up my side business at my house. I have been doing this for years and I have learned a lot
My first 3 years I had a 40 year vet I could ask question to. Been on my own 5
@@traviskelly7082 good info, thank you
As an air conditioning mechanic, I think you did a really good job. I don't know what laws are in the united states, so bear with me. In Canada, you need a license to purchase real refrigerant. The stuff we can buy at a parts store, isn't "real" r134a, but a hydrocarbon cocktail (propane, isobutane, etc.) that works in r134a systems. The catch, is that the weight of the charge and system pressures are very different. The products I'm familiar with require only 40% of the systems listed weight. This leads a lot of people to overcharge their systems, which prevents the ac from cooling at all. Its actually better to under charge than to overcharge. Pressure is great for diagnosing issues, but not great for charging.
Thanks, that’s interesting.
@@1RoadGarageyou didn't show and open only the low pressure, blue doo. You didn't open the valve on the gauge red one, high pressure. Why you didn't do that?
In the US to purchase large quantities of refrigerate you need an EPA license. The small cans anyone can purchase.
@@shawnvanderdoes9823 that sounds really convenient for home mechanics who want to do it right
Lol, you will know if you overcharged it. You will find oil from that AC system leaking from your AC line seals/o-rings. Then you will need to go have the system serviced lol.
I sometimes get myself in trouble when I criticize UA-cam posters, pointing out mistakes and things that they left out? But you need not worry, because your video is the most complete AC recharging video I have watched in the past few days! You showed all the steps. Please take this compliment, as I don't give very many!
Lol tool
Wow! What an honor! I mean, coming from you and all 😂
That was very noble of you. However, this is the one time you should've opened your mouth. Instead you let this youtuber get away with doing a completely wrong ac recharge. As you know, the ac is a closed system, meaning the amount of refrigerant in the system is what will be there indefinitely unless there's a leak. A low charge in the system after having no issues means exactly that. The first would've been to evacuate the system and pull a vacuum on the system. Since it's obvious there is a leak, the next step is to find it. My method would be to let the system pull in about 50 psi of r152a and then spray soapy water on each connection point. Once the leak is fixed then vacuum system down again, more r152a, then recheck. If no more leaks, then a final vacuum for about 45 mins to be sure all moisture is out of system, and then recharge with your refrigerant of choice ( just make sure it's compatible with the oil in the system). *mic drop*
@@brittanywright9646 what the hell is r152a??
@@danroth3962 it's a refrigerant. Same as r134, but better.
Just a tip. Turn off the recirculation system on your a/c when charging, allowing only outside air to flow through the evaporator, which will give you the true pressure readings on your manifold gauges.
good tip man
Never heard this one before. Makes sense great to know
And give you the correct temp reading, you're cooling the outside air temp not the inside cooler air.
Since the compressor speed varies with vehicle speed unlike home hvac, it’s reasonable to assume the pressures increase while driving. This makes it kind of Kentucky windage to get the proper AVERAGE amount of refrigerant in the system for all ambient temps and speeds, without over or underfilling it just sitting static in the driveway. The thermometer in the vent becomes the most valuble indicator
Turn off the recirculation system on your a/c this is the right way to do it you need to use the outside air temperature to add the correct amount unless you recover and recharge by weight!
Many have said this, normally what I do is purge my high side while the engine is off by cracking the red knob just a tiny bit then closing it. You leave the yellow hose disconnected. then i repeat with the process with the low side with the engine on. Then do what your purge process. During the recharge, i use a thermometer to measure the temp on the condenser near the inlet side and compare it to the temp on the high side gage. Try to get the temp on the guage to match the temp at the condenser inlet without going over. Once these are close, usually within 10 to 15 degrees, your system is full. You will note the suction line on your compressor should be condensating. This means there is cool liquid refrigerant making its way back to the compressor to help keep it cool and lubricated. Its always worked for me and kept me cool in the Florida heat. Charge volume specs never actually tune your ac system because each system is different, and it's volume capacity depends on not only manufacturing accuracy but also elevation and ambient barometric pressure. Hence a system charged in denver would need slightly less freon than a system charged in New Orleans. Always go by condenser temp to prevent overcharging.
The refrigerant going to the compressor should be vaporized or the compressor can lock up
@@carltonshore8843 not completely, if the refrigerant is completely vaporized, you drop cooling capacity. Vaporization is dependent on temperature. If the lines aren't sweating and back to the compressor, you don't have enough refrigerant
Just an observation, keep in mind, the compressor is supposed to pump Freon in the gas state.
Great video and info bro!! Hey the only thing that I would like to add is when you screw the fittings down onto your AC lines don’t screw them down all the way because they are known to break the Schrader valve that’s in your AC line so basically screw it down until you see the gauge move and maybe just a little bit turn past that and that should be good. Hope this helps.👍💯
nice bit of advice sir thank you
good advice, you only need to open it, any more will damage the fitting thank you!!!!
I am a pro mechanic and I think you did a fine job yes you will need better stuff to do it for a living but you did nothing wrong good job guy!!!!
Thanks!
@@1RoadGarage How did the AC do a month later? Did you have any leaks?
If you follow this video, it shows how to introduce non-condensables into a system. Yes, air in the hoses at 0 PSI is air at 1 ATM pressure. In the USA, to work on automotive AC systems, an EPA 609 certificate is required. Purged the refrigerant line, but not the high and low side lines. One out of 3. OK. To vent much less refrigerant to the atmosphere, opening the can valve, then closing it will squeeze the air and partially replace it in the hose, then with the can valve closed, purge at the manifold. The refrigerant in the line then expands and expels the air. No need for inverting the can for this step. Gas pressure alone is enough to purge the line. Same applies to the vehicle lines. Open the high and low side connector valves and close them, then release the pressure at the manifold. The expanding refrigerant will purge the hoses. Do this with the engine off, so the low side has more than 15 PSI to compress the air in the hose, then expell the air as the refrigerant expands as the pressure in the hose is released.
Keep air out of the car AC system. It can't turn into a liquid and thus reduces efficiency and capacity. Save the environment by venting as little refrigerant as possible. Don't flow refrigerant to the atmosphere by venting it as shown in this video.
Might take a look to see where the sight glass is on the vehicle AC system. Learn how to use the sight glass in addition to your gauges for charging. Remember, if you have non-condensable gas in your system, the sight glass will always have bubbles. Only a system without air in it will be able to fully condense the refrigerant into liquid to be seen as no bubble liquid in the sight glass.
I understand that the refrigerant must be charged through the low pressure line in gas form and through the high pressure line in liquid form. It is not good to charge liquid through the low pressure line. Is that so?
@ You can charge through the high side, but only after the system has been repaired and under vacuum. Liquid can be charged by weight into the high side. If you try to put liquid or gas into the high side, the tank being lower pressure will pump out the refrigerant into the tank possibly over filling it and making an explosion hazard.
Some refrigerants are required to be added as a liquid, as blended refrigerants can be distilled by boiling off the higher vapor component first, which destroys the refrigerant glide. Look up blended refrigerants for more info.
@isettech
Reference ”In the USA, to work on automotive AC systems, an EPA 609 certificate is required”
That statement is true ONLY IF you are being compensated ($ or bartering).
“Any person who repairs or services a motor vehicle air conditioning (MVAC) system for consideration (payment or bartering) must be properly trained and certified under section 609 of the Clean Air Act by an EPA-approved program.”
@@CWK090 This is one of the many things that make me happy to live in the developing world, definitely the "free" world is not free at all, everything regulated, everything normed, everything limited, everything controlled.
And it is beyond you to comprehend why?
Your video helped me fix my kids AC! Now I have some tools, knowledge, and experience to tackle future AC problems on any car. All due to you!!! Thank you very much for your *entertainment* vid!!!
I have watched a lot of these. You literally are the only video that is specific on what valves should be open and what are closed. Thank-You!
if you were 24 ounces low on refrigerant then you have a leak somewhere. I would like to have seen you take it down to vacuum, say, 500-540 microns, and let it hold there to watch any decay in pressure over about 15 minutes time. Then you could have just recharged it to factory charge. Other than that, nicely done. I'm happy to see you purged air out of the lines before putting it in the system. So many people forget that step. When I do AC for myself and friends or whomever, I always put a blower fan up to the rad/condenser to simulate some driving. thumbs up!
How do you pull a vaccuum on it if it has refrigerant still in the system?
I just rebuilt my entire ac system l most anyway after recharging twice only to not have ac afterwards. Third time was a charm thang god. Cold ac is a blessing
wow maybe that's what I need to do. I've replaced my evaporator/condenser, compressor and it still struggles to get cold on hot days. It used to freeze us out! The dealership purged and refilled it because they can't figure it out. It got slightly better but still not cold. So maybe a third time will help! I'm thinking that there is some crud in the lines somewhere....
It's nice to see others take on something new to them. My opinion is just run it until it starts blowing warm again, otherwise you're throwing money away! If it's lasted 28 years so far, it'll probably be fine for at least several more years with the top off provided you didn't overcharge the system and hurt the compressor.
If it is leaking anywhere, it's probably leaking at the service ports and compressor seals...could try soapy water and see if you get any bubbles to avoid having to add dye, but it's probably not a big deal if it has lasted this long. Just run it until it becomes intolerable before going down the rabbit hole of parts replacement.
I'm about to replace my entire system in my 98 Jeep Grand Cherokee and I bought the gauge setup and I want to do this the right way so I am here learning and this is one of the best videos I have come across so far. I really want to know more about charging a new system and removing the old refrigerant from the old. such a good job on this video thanks brother
Unless you are evacuating a system or drawing a vacuum, you do not need to open the red (high) pressure valve on the manifold set. The gauge readings are irrespective of the manifold valve positions. Gauge dials read with manifold valves open or close. The valves control the flow from the yellow hose to the respective colored valve.
It took me days to figure this out. It's amazing how few people explain the manifold function. Thanks.
Can’t get much colder than that. Smart to keep it safe like you did. The beauty with these old trucks is they are simple and when they work they don’t need fixed until they break. I’d bet yours will blow cold for years to come unless the compressor fails. Good video!
Well, when it comes to automotive AC systems whether mid 90s or later vehicles, this is no different than my 2012 Jeep or my 2013 daily driver Nissan which the latter was low on refrigerant. Same procedure and now it's more comfortable driving to work in 110°F+ temps here where I live.
That system was low on refrigerant for a reason. There’s a leak somewhere. Refrigerant isn’t a consumable.
I do the same, but like to run a little refrigerant thru the low side line to purge as well. I never open the high side at the manifold, so that is that. If the system is empty, and repairs are done, I evacuate the system with a vacuum pump for an hour, check for leaks, then add refrigerant according to the levels indicated by the manufacturer on labels under the hood, looking for, as you said, pressures to be proper with the ambient air temp, and look for cold air out. Thanks for the vid, you do it right. Cheers!
The video is a really good video for any DIYer to follow. I'm a DIYer I work on my Class 8 truck. Your information right on.
U did pretty good, accept for a few things. 1. U should purge all the hoses. 2. Chevy typically have a back pressure regulator set for 28 psi. So no matter how much freon U sucked in the back pressure will always b 28 psi. U should always charge an A / C system by weight or temp, not by pressure.
What do you mean by weight or by temp ?
Please clarify in detail.
@@northwestrepair with a refrigerant scale or by ambient temperature
Jimmy, you've come a long way. Another good one man
100 percent correct. You can only get the best reading on your gauges at 2500 rpm when the car is stationary. Otherwise you get lower readings at idle.
Very wise to stop when you did. The system is performing very well, the difference between the pressures is correct.
Yea I blew out my compressor trying to get get the pressure up to what is recommended
Came across your video and provided me with directions to proceed. I saved it to refer back to the information. Thanks buddy, from South Texas where we are in 100° F heat dome.
Hey there! Just a quick note to add, and please feel free to correct me if I’m mistaken. It seems like the high and low lines weren’t under vacuum, which means outside air might have been entering your system. Ideally, you’d want to use a vacuum to remove any air from the lines. Once that’s done, make sure to seal them off to prevent any outside air from getting back in. This way, your system stays clean and efficient. Hope this helps!” 😊
Good job plain and simple now all we need to do is fix it so home owners can do this also
Dude, that was awesome, and AC units are always unpredictable.
But as long as it's blowing cold, you're good.
That’s what I’m thinking
Jimmy I liked your video very much you explained all the processes very well.. I just finished working on my 95Chev just about the same system as yours. I only got the inside air temp down about 50* F until I drove it at freeway rpm’s then the temp came down to 45*. I was happy with that. The outside air temp was 98*.🤠
For a DIY, you did great!
Only once thing I'd like to add, it's a good practice to turn off your air recirculation switch while charging the A/C at 1200-1500 RPM, as the charging chart temp is normally taken as outside ambient air.
Positioning a shop fan (24",36",Etc. drum type) in front of the grille blowing air into the condenser will simulate A/C performance while going down the road. Watch the gauges and see the pressures drop.
While you're at it , it wouldn't hurt to flush the condenser out with a water hose if accessible. From the inside (engine side) out. Not internally flush , but externally.
I just redid mine, and it works better than it ever has. I have a handful of tricks I developed over the 26 years I've owned this truck. I also perfected the coolant mix and radiator swap.
Just towed a trailer in 97F Austin heat, full blast AC, never budged off the 180F stat set, other than a flicker after encountering a traffic light. 4700lb trailer. These secrets remain unknown because your host insulted be and canceled some posts. Carry on.
hey no worries mate, as temps go up pressure will also go up, you did a great job, if it goes low again then it is time to look for a leak, if you have to recharge a 2nd time then you should vacuum the system and also add some oil but for now you are solid gold!!!
I am also a DIYer.. on the r134a chart (i.e. 175-210psi on the highside), i rev to 2500rpm to get that highside range.. that would also be safer.. avoid high pressure hose from bursting.. that's just mu process :)
Place a fan in front of radiator that helps to simulate a driving condition it changes your pressure readings
I don't know for sure but I've heard where one must vacuum all the refrigerant out and moisture before adding new refrigerant I've always heard that and to use a scale to measure how much to put back in according to the label under the hood
It's the best way to know you are not undercharging or overcharging. Charging based on pressures is tricky and inaccurate.
Stay Coooool! LOL Yes. Many do not use the vacuum like they should. I rent it from the local big boys. There is almost always some moisture in there after the years go on. Also, I'm sure you know, but if you suspect a leak - like your cold no longer cold in a week or so, you can use that fancy multi-legged thingy to push leak dye and UV light around (night better).
BTW, save your gauges that come with some of the "rebate" canisters. You can use them on the refill cans, later.
All I have to say you is you did an awesome job
Not a pro here. But I have always only charged gas into the low side. Meaning the valve on the can is up. Tilting the can or putting it up side down will give you liquid. If you want to empty a can. Hang the can upright into a small bucket of hot water. I do the same with 30lb jugs too. Just makes the gas charge a little faster.
Great video. I have that gauge set and my system needs Freon added. Your instructions were what I needed to have the confidence to get this done.
I too have a GMC, it too cools better when the pressures are lower than those that a pressure chart says what they aught to be. When the pressures are brought up to the charts specification, the temp rose from around 44-46 to 52 or so. Keep the pressures slightly low for the coldest air. Rf-TN
Idle your engine to at least 1500 rpm. Your pressures should get to the idea measurements. Good job and explanation!
I think the low side should also be purged before connecting the yellow line to the full can. Should be no need to purge the high side since refrigerant will never be added there.
In a two-phase system i.e. where you have the refrigerant existing as a liquid and a gas at the same time which is what's happening in both the evaporator and condensor when it's working properly, the pressure depends only on the temperature of the heat exchangers. Once there's enough for the proper two-phase cycle to occur, adding more refrigerant won't increase the pressure. All you're doing by adding more is increasing the proportion that in the liquid state. Too much will damage the compressor if liquid enters the compressor inlet from the evaporator or if the condenser is too full and backs up into the compressor outlet. The compressor wants gas only - liquid is bad. This is why there's a specific quantity of refrigerant specified. The only way to know for sure if the correct amount is in the system is to pump it all out with a vacuum pump and then refill it with a measured amount. It's measured by weight, not pressure. The gauges can give you an indication of the system performance, but they cannot tell you how much refrigerant is in the system. There are other potential causes of abberant pressure readings including a worn compressor, bad expansion valve etc.
Charging a properly evacuated system is much much simpler if using the "delta drop" procedure.
That is, at 1600 rpm, measuring the input air temperature going into the evaporator coil and the output air temp coming out while charging slowly and intermittently (to stabilize) to get the maximum temperature difference.
Thats the ONLY way of accurately determining the exact proper charge.
Also the accumulator will be warm about half way down and cold in the upper half. That tells you that theres reserve refrigerant in the system.
Youre welcome. 😁😎
Great video! Very professional, simple & straight forward.
Question did you purge the suction and discharge? I noticed you purged the feeder hose but you didn't purge the other ones! Anyways great video... I'm a 29-year service technician from Nashville Tennessee
I’m in middle TN as well. Currently trying to solve a rough idle on my ‘05 Envoy. Check my latest video I just uploaded. Here’s a link to my fuel trims: Live Data From 2005 GMC Envoy! Help Me Diagnose Rough Idle!
ua-cam.com/users/shortstTO8Oc_T1k0?feature=share
@@1RoadGarageignored the question entirely.
When the weather got hot this year, my truck (a 2000 Ford F-150), also was not cooling. I found one of the Schrader valves was leaking. So, after replacing the valve, I recharged the system and it started cooling like yours.
Great video, I would add one little point. When youre ready to charge, purge the low pressure (blue) hose as well as the yellow can hose.
Should the red and blue hoses be bleed of air too?
Only if they're opened at the manifold. The high pressure side doesn't 'feed' into the system and the high pressure manifold valve didn't have any reason to be opened in this top off scenario. The low side should have been bled by cracking the manifold valve open slightly with the yellow fill hose side disconnected/open to bleed it out, then reclose the manifold valve. Yellow fill is always bled every time you connect a bottle/can.
Very well done. Only thing I'd add is; check to see how much refrigerant a vehicle takes(should be by the weight). You don't want to overcharge a system.
I got pumped for you when I saw your vents shooting out 30degree air haha that's awesome . Great video buddy
Many AC/Heater Systems the fan blows first through the heater core then through the Evaporator,if the control switch does not shut off the hot engine water going through the heater core this will cause the AC air to be a mix and will be warmer than it should be,check for a electric or vacuum
Switch in the hot water system,on semi- trucks I have installed a manual
Shut off to stop the hot water in and out of the heater core!!! This brings a big dro in AC vent Temperature!!!❤
Jimmy, could you make a video showing how to replace your coolant on your 95 suburban? I have a 1998 gmt400 truck and am planning on doing this myself soon. I always watch your videos because you are always so thorough and meticulous about everything. I assumed you already would have a video of this but when I checked and you didn’t, I figured I would ask if you’d make one if your coolant needs to be changed. Thanks either way, love the videos, from Jimmy to Jimmy👍👍
The delta T on car AC is 30F, so if it's 100 inside car it will blow 70, there is no fixed ok temp, when cool in car 75F it should blow about 45F. Too much refrigerant will damage compressor. Charge for 30F delta and accumulator canister frosty to touch 70-80% of canister. If system is completely flat you have to fix leak, evacuate it, and recharge correct weight.
Awesome video, this is in my near future too since the cost of doing this at the shop will be more than buying the necessary tools. Thanks✌
Hmmm, after 2. Can still no pressure increase on the low side. Sound like the expansion valve is stuck. This regulate the flow of refrigerant throw the system.
Excellent video... For sure will help a lot people saving money out there. To know a good and honest mechanic shop that you can trust in this days is very hard and its sad to say it.
Thank you so much for this great video. May God bless you.
My Vivohome gauges do not have a schrader valve to purge the air before charging. OK I just watched an AC pro purge his air by opening the yellow charge line at the gauge even though he had a Schrader valve on his. So if you don't have that valve, that's another way of doing it. The main thing is don't add the freon until you purge the line of air. Hope this helps others like me. Thanks for posting.
Don't get me wrong though I like your videos I like your style and I like the way you present doing your own mechanicking Air conditioning is always tricky what you doing really well job of explaining and showing what one should do thank you for that
Is that adapter included with the kit you bought @ Harbor Freight? Any other adapters?
Good point at the end of pointing out if you register 0 psi on guages you need to vac out air and moisture and be sure it holds showing no more leaks. Just had to order vaccuum and freon leak detector to find and fix before attempting refill.
I saw comments from pros that said you did a great diy job and I fully agree! And yes better a little low than high. I usually just check with the thermometer and add until I hit 40 to 45 and the compressor runs constantly in full cool mode. I personally don't like the super cold air blowing on me. I'd rather chill out... Slowly! Later.
You really need to recover all, check for leaks, and vacuum and fill to how much your OE manufacture says to have in it.
Just checking by pressure is a great way to overfill your ac system and damage your ac compressor.
Thanks for the input.
I'm finishing a compressor replacement on my 05 t&c today. I thankfully saw before getting into this project that pressure by itself doesn't tell you how much refrigerant needs to go into the system.
So I bought a kitchen scale, I 'obtained' a copy of the factory service manual, and figured out exactly how much oil & refrigerant I need to put into my system.
So I'll be able to measure the exact ounces coming from the scale into the system and I've got the factory manual which has great info on how exactly to perform the tasks I need to do. Already swapped compressor, seals and o-rings, pulled my vacuum & no leaks.
Just need to make a final trip to the parts store cause my stupid can tap was machined improperly and doesn't fit the acme 1/4” connectors like it should.
Hopefully I can pull this off and get this AC working strong before a thousand mile move!
I like those gauges, they have a port for the vacuum and the freon so you can vac and then charge with out breaking any connections,
Probably a pretty good guess on how much to add for you. Mine was completely open, so I had to grab new O-rings and vacuum test the system. I refilled by weight.
I am going to pressure test this weekend again, mostly to verify it's the relay that went bad. (I can't just swap out a $10 relay in my car. It's a whole control module.)
Just for your edification, you can buy adapters to go on a 1234 system, because 134 will work in that system. When you get to about 11% of 134 in a 1234 system, you remove the fire hazard that the 1234 carries. It was well-known in Europe for causing engine fires quite frequently when they first started converting over to it. The other problem is is that the reason we use 134 is because it doesn't damage the ozone layer but they still can't explain why they're forcing us to convert over to yet another design except that the 134 patent has now expired. Just like R12 did a couple of decades ago.
Many vehicles actually required elope side pressure to be somewhere around 30 to 35. The greater differential between the low-pressure and high-pressure which is usually around 275, the colder the air will be after it goes through the evaporator.
I was thinking just that. I don't know why they would stop using r134 considering how much better it is compared to the old stuff.
It's only better according to the DuPont Scientists who said it was after the patent on R-12 expired.
@GlennHamblin r-12 worked great but killed the ozone bad. 134 works pretty well with way less side effects to the ozone. Why they released 1234 I have no idea
In theory it's because r134 is a greenhouse gas 100-120 times more powerful than CO2
@@brianherndon5820
R-1234 YR
3 times the price.
What about the outside air that's in the red and blue hoses? Does this also get purged before opening high and low side valves?
No. These lines are sealed.
Your video helped me fix my AC
When adding refrigerant, never add liquid (high) though the gas ( low) side. The refrigerant instructions state tipping the can, however that introduces liquid into the gas side of the system, that’s how internal restrictions are created. Only top off with gas. It will take longer but ,, that’s the correct/ safest way to top off refrigerant .
Many garages/ DIYrs will do it incorrectly to save time ( at the moment) or ignorance. When the system efficiency drops, it will take much more time and parts to correct the previous errors.
In america Vacuuming ac systems Standards are 10 minutes at 20 Inches Of Mercury to Boil off any water in the system if it passes 10 minutes no need to continue if it dosent then you need to do a 30 to 40 minute Vacuum Jimmy @1Road
You done right. Any automotive AC does better driving. The compressor rpms circulate the freon better. I probably wouldn't add anymore. Who's to say how accurate the guages are?
Great video, the only thing I would say is if you had to put two cans of freon in you've got a leak somewhere
The straight end of hosed connect to the gauge set.
There is a label on your vehicle under the hood that tells the amount of refrigerant your vehicle can hold. Sometimes it is less than the 24 ounces you added to your vehicle. So you may or may not be ok depending on your vehicle.
I would also check your fan. I believe this is a fan clutch vehicle and it's likely weak / needs to be replaced. That'll definitely help with your sitting still pressures
make sure your aircon motor sometimes not engaged, if not it will not last long. thanks for your effort.
Was just about close the video out just before your said “ if your system has no pressure ……”
& guess what, I went outside to check the pressure amd there is none on high side and low side.
Looks like I gotta find the leak. Appreciate the video
Luv the way U make these videos and guide's
I have same truck and your suggestions are perfect to me !!
Hello, very good review!. But can you please enlighten me. You purge the air present in the filling pipe (yellow), but there is air present in the low pressure pipe (blue)?, is there a way to purge?, example air conditioning stopped, slightly open the blue wheel, to let out a little air and old freon through the yellow pipe and quickly close, then do the yellow as you showed in the video?. Thank you in advance
I'm just learning how to properly charge auto A/C systems with a proper set of manifold gauges so I've been watching a lot of videos. I noticed that some pros read the pressures when the engine is revved up to 1,500 to 2,500 rpms. I wonder if that's why your readings are low.
HI, for sake of argument , lets say your system takes 34oz of refrigerant...it will work better(believe it or not) with 31-32oz. Also wash your condenser rad with a garden hose it will help for better results.
thanks for the vid, be well !
What about compressor oil? How to check whether it has enough or less oil?
7:15 Didn't purge the high and low pressure hoses.
I charge according to the high side. If the low side is way off, you likely have a restriction. My car was last charged by a pro (I used to be, still universal refrigerant certified) to the weight specified by the manufacturer. It wasn't super cold so I checked it myself and it was 15psi low on the high side. Brought high up 15 psi and I can blow 42 degree air at 115 outside. 36 at 100. When it can get really hot like 110+ outside, you want to make sure you are at the low end of the range when charging at lower outside temps. In regards to yours at 80, I'd add maybe another 10 psi high, but I wouldn't open a new can for that little change. But remember what I said about temp, it can get over 120 here and high side can skyrocket at that temp while stopped at a light so restraint needs to be used when charging.
Look at your gauges again carefully there is differant scales for different refrigerants listed on bottom sbove needle stop pin. The manifold reads 3 differnt types refrigerants. I believe your eyes are focused on the outter black numbers on gauge.
Awesome video, I got my 03 avalanche last year and hasn't had any AC and I have to fix this soon
You can do this without having to drive around. Just put a high output fan in front of your radiator to blow air through your system just as if you were driving around. If you dont have enough airflow through your condenser, the system will not operate properly. The fan on your engine will not pull enough air through the condenser at an idle. Especially if you have electric fans.
Rev the engine at steady 2000rpm during charging will do as opposed to driving around
Thanks for posting, like you I was going to try this, but all the pros keep saying you have to evacuate completely and then put in the exact amount for the perfect amount. How you looking?
Did you have the rear air on as well when you topped off the system. The rear air has a major affect on the ac system
Working properly on these vehicles, rear air has very little effect. My high side pressures rise 15 psi and my low side about 3-5 if I turn the rear blower on high in my 97 Express van. If the rear TXV hangs open, the system will not cool well though.
And the normal Air that is in this non purged red and blue hoses, are you pumping this air into your A/C and contaminate it ? Or do you purge the air out of this red and blue hoses first before you open the circuit , because you want to 100% avoid any air that goes in your system even if it is a tiny small amount .
Your pressure could be low because you have a leak. Did you verify that by recovering and measuring the amount of refrigerant removed minus the system capacity? Vacuum test? Where did you lose it? Otherwise what you put in will leak out. If you open the system once you find the leak and fix it, consider replacing the dryer.
Great video. I have a Schrader valve leak and need to buy the tool to fix that before adding refrigerant. I have the same manifold set that you do.
So if you look at your low press gauge Blue when you are looking at the pressures, you should also look at the corresponding temp scale for R134 on the gauge face. Many over look the it since the print is small, but its the temp that really matters. If pressure goes up the temp goes up. Also, blue is low pressure/evaporator inside the car cabin.......red is high pressure/condenser in the grill of the car. Evaporator should be cold absorbing heat and the condenser should be hot rejecting heat. The law of thermodynamics is heat flows from hot to cold, absorbing heat in the car cabin and rejecting heat at the condenser near the radiator.
You did a great DIY on this one.! Thanks for the entertainment.
It would have been good to first to pull a vacuum on the system to make sure it doesn't have any leaks. The fact that you had to add 2 can of R132 A tells me that you do have a leak and your fix is temporary. All in all good video , this is how we all learn. O'Reillys Auto here in Bozeman will lend the gauge set and vacuum pump to make testing and recharging with very little cost
pulling a vac on the system would require dumping all of the 134 out of the system, without a recovery device this is a bad idea. It looks like a GM that's a couple decades old. A leak detector is a better idea
Yep a sealed system that leaks isnt a sealed system lol
When I charge AC I generally look for the high side to be about eight times whatever the low side is. When that happens cold air will come out of the vents. My high side pressure are always higher than your chart
Good video, wondering if compressor is going bad with the low pressures? It’s working is what matters, I added 12 ounces to my Toyota Camry and working fine
Over filling is worse then underfilling for ac systems you didna great job Jimmy @1Road
You made it be a succes, definately but you still have to find the leak, great video.
Where did you get the temperature gauges. Also what app is that on your phone for temperature readings. Thanks
1ROAD, question:
If all I'm doing is wanting to top off my system, and there's already refrigerant in my accord, if I do your process, I wouldn't need to add the entire amount of ounces
To my system right??
Would this be just adding in any that I may be low on??
good job for a diy'er, always stay on the cautious side and DO NOT add tooooooo much 🤠