I haven't watched cable tv in close to 20 years. No news, or even the weather in about 10 lol. I'm in my early 30s too, got tired of the bs a long time ago, aspecially the news, it makes you depressed seems like. I go outside and do stuff, love me some youtube automotive videos though 😄 it's good for ya
@@motov8-garage832same here. I'm in my late 30s and tv is nothing these days. Used for video games once in a while. The news was only watched for the weather toward the end of my TV days
Good job. I'm an ASE certified mechanic of 30 years. People in my town are amazed that the AC works on my 78 f100 farm truck. They can't get there 5 year old vehicle to blow cold air.....
You nailed it. Awesome video. Compressors don’t die they are killed. Your failing expansion valve is what killed your compressor by not regulating refrigerant flow properly the compressor wasn’t getting enough oil and seized. Don’t replace a compressor without figuring out why it died or else you’ll be doing it twice. I’m a refrigeration guy 👍🏻
We had a pererbilt eat 3 last summer. I got blamed for the backwards orifice when the second one I did died. I pulled it out with needle nose pliers, held the new one beside the old to grab it so I'd get it the right way. That truck ate one every spring.
I no longer believe A/C to be magic! Uncle Tony explained how it works, excellently. My dad was an engineer for Harrison Radiator Division, General Motors Corporation. How did I not know the workings of an A/C unit?!?!!
Some of the old style compressors are able to be used as an auxiliary air compressor. Since they store oil in a sump rather than relying on oil flowing in the system they will work fine without a closed loop system. Can be super handy having an engine driven air compressor with an electric clutch.
I've been messing around working on my own AC for 30yrs and can usually make things work "pretty good", you easily doubled my grasp of the system with 1 video. My Dad spent 40yrs as a Chrysler tech and he explained this to me a dozen times but never in a way that really came together into a complete picture in my(feeble) brain. He's 86 and I'm doing most of the work on his Dakota daily and '79 HotRod Pick-M-Up these days, I'm going to sound like less of a rookie next time I work on his AC. Thanks Tony
Love this kind of content. Currently trying to become comfortable w ac systems so I can repair them in my classics. Would drive them way more with working ac
Tony, Thank You for another video for we folks who are not racers but only want a solid daily driver! RRRRooooooLLL up Your Windowwws, damn it! The Air Conditioning is on!!!!
Youve given great advice; but for those people who choose to do it themselves (with an R12 such as the 72 has), please do not use butane as a substitute for r12. Until my retirement, i checked what type gas was in the system of EVERY a/c system i worked on. You never know what is in it! You'd be surprised as to what is in some of these vehicles. Also, for those considering doing a conversion from r12 to r134a, be advised that r134a is far less efficient at cooling and takes a lot longer to cool down a vehicle. I did conversions on a European import make when the factory offered a conversion gas kit and not one customer was happy with the results. Finally, if the vehicle is more than 5 years old, i replaced the schrader valves as a part of a normal recharge, thus avoiding a potential comeback from a work valve. Enjoy your videos, keep it up.
The effective replacement for R-12 what I’ve been told is R-152 which is the compressed air in a can for blowing dust out of your desktop keyboard. You throw about x2 the weight of r-12 n it does the same thing. Better than r-134 conversion
@@jayslpstapes519that's what I've heard as well. R-152a and under half the weight as factory R-12 charge for the system to run well. It's slightly flammable but nowhere near as much as butane propane mix. It also happens to be 10x better for the environment than R134a and infinitely better than R-12. I suspect 152a will be making a comeback now that our global warming potential for new refrigerant systems needs to get under 700 by 2025. R32 is 675, barely making the cut. R134a is 2000 ish, r152a is 170. Propane is like 3.
I watched this and thought Tony did a great job explaining for someone who isn't experienced with A/C. I knew the comments were gonna be full of scientists who just have to display their knowledge on thermodynamics and how a/c systems work. It's like every video he makes everyone has to correct and critique when they miss who the videos are even made for
I've always favored the txv (thermostatic expansion valve) system with the receiver drier over the orifice tube and accumulator drier on the suction line. They are WAY easier to add a little charge to if the system is low via the sight glass vs having to pull the charge and weigh in the correct amount on an orifice tube system. Anything else on an orifice tube system and you're just guessing. The other thing nice about a txv system is it can react to different operating conditions and meter refrigerant accordingly. As a former transport refrigeration and air conditioning mechanic of many years I think you did a great job explaining the system!
Just to clarify. The compressor compresses the freon into a high pressure gas. 300+ psi inside the compressor, 200ish in the high side line. That generates a tremendous amount of heat, over and above what you are actually trying to remove. The evaporator is the first stage of the system, where the heat is absorbed. The condenser is the last stage, where heat is transferred to the outside world. The compressor does not force the freon to turn into a liquid. When the hot gaseous freon gets to the condenser, it is cooled by the air going over the condenser and condenses the freon into a liquid from removal of heat and a slight pressure drop across the condenser. Then it is off to the expansion valve, orifice tube, or POA valve (pressure over atmosphere). This is exactly why some systems have 3 service fittings, high, low, and an aux/liquid port to check the pressure drop thru the condenser. The cooling does not happen in a valve, that is a longstanding myth. The cooling is from the freon boiling in the expansive volume of the evaporator. Freon starts boiling anywhere from -45 to 5 degrees depending on the type. The freon changing from a liquid, by boiling off in the evaporator, is where the cooling actually occurs, by absorbing heat. I never saw a pot of water instantly boil off, neither does freon. You can literally pour some types of freon on the floor, then it boils and it only boils at the surface of the puddle/droplets... There are refrigerants that can sublimate, and they are not used in cars. Sublimate means it skips the boiling stage during expansion, and instantly turns into a gas. Those are used to get to very low temperatures in manufacturing and storage. A receiver dryer is always on the high side of the system, and an accumulator is always on the low side, if they are equipped. Some systems have one or the other, some have both. Neither are disposal at every service because the moisture can be removed easily with a vacuum pump and a heat source. Water boils at 72 degrees in a 29" vacuum. And that is how you get the water out of them, apply a vacuum to the system and if needed apply heat to the desiccant.. If you have a compressor failure, or mixed refrigerants or oils, then that is a completely different issue, and either of the two are the least of your problems because far more needs replaced.... People replace dryers/accumulators to save time, because they want a far shorter vacuum cycle. Time is money, kind of thing.... Not because it is a disposable part once the system is opened..... I taught this, for nearly 35 years...... Most people don't understand how ac actually works. You cant make cold, but you can remove heat.....
This explanation, exactly. Tony’s explanation is fine from a practical sense when understanding how to swap parts to make things work but there are a lot of inaccuracies in his explanation of how the system actually works. Once it clicks for you how it works it makes so much sense. I think of it like this and correct me if I’m wrong. Cool low pressure liquid to evaporator, which makes cool low pressure gas to the compressor which makes hot high pressure gas to the condenser which makes hot high pressure liquid to the expansion valve or orfice tube (etc) which makes cool low pressure liquid to the evaporator. That’s the whole thing in a nutshell. It’s the boiling and condensing (latent heat/phase change) that moves the heat from one place to another. Evaporator takes heat from the inside air to boil the refrigerant. Condenser sheds heat to the outside air to condense the refrigerant. Thus the system moves heat from inside to outside. So simple.
Thank you great explanation. Is it true that it's helpful to run the A/C occasionally during off season to circulate the lubricant? I repaired my 1965 Ford A/C in 2012 and it still blows ice cold - every week or so I turn the A/C on for a few seconds hoping it helps.
a good explanation there, I remember a course I did way back in HVAC days when the Vapour Compression Cycle and the Latent Heat Change was first explained to me, once you understand the physics behind it, the penny drops.
I remember the first car we had with air conditioning. We drove it when it was new, up to Canada in the Summer for the World's Fair. It was so humid, the air conditioning was dripping waitron in the passenger side floor. We went to a garage where they spoke French, they told us it was normal and that the humidity was overwhelming the air conditioning drain. All of the garage technicians at the garage in Canada wore white doctor coats. After Canada, the A/C drain was never a problem again. The owner's manual said to run the A/C at least once a month, even Winter, for certain number of miles, to keep it lubricated and from seizing up. It didn't cycle with the defroster, like they do in newer cars, but mentioned using the A/C to defog the windshield. We had the car for 10 years and the A/C only lasted for about 5 years., but with quite a few miles on it.
If you are working on an old Mopar and you find a valve inside the compressor where the low side hose attaches take it out and throw it away. It's called an Evaporator Pressure Regulator (EPR) valve and they must have been trying to outdo Ford for better ideas the day they came up with that one. It served no good purpose and did nothing except malfunction when you least need it to, like on the way to a wedding or a funeral. It was supposed to help keep the evaporator from freezing. Love your channel, Tony. It reminds me of those days in the garage when going home looking like a grease monkey and with genuine busted knuckles were everyday realities working on those old cars.
Good job explaining this Tony, and covering all areas. Strange as it may be, our first local Mopar down under with factory integrated air, was in 1969. In 68 you could get a dealer fit under dash system. In 1970, the system was changed to run a Tecumseh parallel twin compressor, so that V twin died off here. Good work. Highly regulated down here, no such thing as home charging, has to be done by a licensed operator, and they know how to charge!
We forgot the theory, change of state is critical, we also have heat transfer from condenser and evaporator, txv and orifice tube operation, as in change of state, ALSO the refrigerant carries properties such as a direct pressure to temperature relationship..
I’m on the north side of 50 and I’d never fully understood the a/c system before. I’d heard the terms for things but never had a complete run through of what happens in a a/c system. I’m not to proud to admit I ‘rewound’ this video acouple times to listen to how you described some points a second time.
I remember years ago going through an AC class and didnt remember a thing and got the certificate. Was it the class or me I dont know but probably both. I learned more in this video than that class so thank you
Really good to undestand basics of A/C on older cars, also I see most of the old stuff still make it's way into newer cars aswell! If possible, make a video on the differences from a carb that has the A/C stuff and one who doesn't, I think there's some parts needed on those carbs, I'm not 100% sure. Great video as always Uncle Tony!!!
Replacing the "dryer" is kind of an outdated thought from when people may not have fully understood the systems and/or vacuum charging wasn't as common. When you pull a vacuum on the system, you're not just evacuating it of air, you're boiling the water out. Just like how a pressurized cooling system increases the boiling point of water, vacuum decreases it. On a nice hot day, with a consumer grade vacuum pump (mine is a lower end Robinaire... not that different from the HFT ones), you can generate enough vacuum to boil the water at ambient temperature (from memory... I think this is around 90F at 29 inches of vacuum... so... the hottest day of the year is a good time for A/C work 😆). When you boil the water, you're boiling it out of the desiccant too and "recharging" it. Also... If you do buy a new dryer, it's not like they come sealed. The last one I did replace just came with plastic caps over the fittings so the threads didn't get damaged. New ones need vacuumed down too... and usually need some amount of oil added to them before installation. Where you _do_ want to replace your dryer/receiver/accumulator is when you have a catastrophic compressor failure or the system has been open for a long time. Running the risk of pumping tiny bits of debris out of one into a new compressor isn't worth the few dollars it saves. I wouldn't bother to do it for something like an o-ring failure on a recently working system though. Fix the leak, vac it down, charge it, send it.
Good video, you should be an autoshop teacher. AC and 5 speed were the best things I ever put in my 66 Chevelle. I got ac licenses years ago, but quit working on them myself except for emergencies.
"The closest thing you can come to hell without actually being dead is under the dashboard of an air conditioned classic car" 11:14 I am a commercial/industrial A/C technician and did a retrofit on my friends 1964 Thunderbird. Zen state all the way in the interior.
So helpful! Thank you so much for going over how the basics of the A/C system works. I recently purchased a ‘66 Impala sedan with factory installed A/C (still looks like it has the factory-installed compressor in it because I can still see the remnants of the Frigidaire sticker on it) and have been trying to figure out what to do to get it back in functional order. Your explanation helped out a TON!
Back when I was younger and didn't have to nickels to rub together I used propane as my refrigerant every now and then. I don't recommend anyone doing that, but it works. Just got to remember and realize you have a ticking time bomb under the hood and dash of your truck/car. Propane or not I highly recommend a fire extinguisher in any vehicle new or old, it may save you or someone else car from going up in flames.
The Dart has what's called a Thermal Expansion Valve or TXV for short. Most systems now use an expansion valve instead of the orifice tube. The new expansion valves regulate off of pressure/volume alone.
Derek ,hell of a mechanic ,and more ,Dan from DD rock on brother ,,Uncle Tony is the real Deal Holyfield and probably forgot more than most people know , imagine being able to educate just off the top of your head , CHEECHIN MINT !!!!! JUST A DOWN TO EARTH DUDE , UTG RULES !!!
Thanks Uncle Tony for making this video, it was sorely needed! I, like many others just needed the shop teacher breakdown of what everything is and does, especially the valves and lines up close to the firewall. Keep the Chrysler guru knowledge flowing!
Pretty good explanation with the exception of you aren't compressing liquid as that's not feasible and the condenser is converting that gas into liquid there. But I'm sure you helped some people understand better. 👍
Ty for this vid man , you're a worker . You explained this very well and helped me as I'm apartment maintenace and just learning this stuff . With the ol super heat n sub cool stuff . Piston / orfice vs Txv type and latent vs sensible measured saturation change etc
These kinds videos are the reason I started watching you and quickly subscribed ! Soup to nuts common sense explanations that make sense at least to people that want to fix their own stuff !
Good info. I had some rental properties in Georgia and all had heat pumps so to save money I took a HVAC course and watched a few TH-cam videos which allowed me to successfully install and maintain the systems. I live in the Philippines now and brought all my HVAC tools and vacuum pump since I had to install 4 mini splits on the house we had built. The Filipino installers don't use vacuum pumps. I bought a 2002 Suzuki Carry mini truck that has a 660 cc 3 cylinder engine. The A/C lost the charge a few days after I bought it. There was an o-ring leaking so I replaced all o-rings pulled a good vacuum and recharged with R134a and it is ice cold in the tiny cab. I also added an ounce of oil for good measure. It is cool because the condenser isn't in front of the radiator, it is beside the radiator and both have electric fans.
I'll never forget watching someone at a local garage adding a can to a system. Is it blowing cold yet he asked another guy in the car. No he said so they go for can number 2. All of a sudden it sounded like an M-80 went off under the hood. Another guy thought the battery blew up. Turns out a pressure line blew. Maybe one of you AC guys could explain what happened. After seeing that I never tried to recharge a system myself
An A/C system is just a heat exchanger. The pressure drop through the expansion valve turns it to a gas which makes it low pressure which makes it cooler than the ambient air. As the freon in a gas state passes through the evaporator it is removing heat (energy) from the cab by absorbing it into the freon. The reason the freons temp rises so much after being compressed is from the heat (energy) that it removed from the cab being compressed to a much smaller area, it concentrates the heat. Most of the heat coming off of the condenser is concentrated heat from inside the cab. It's removing the heat from inside and releasing it outside therefore leaving the air inside cooler. Hot air is energetic air. When using the heat you are transferring energy made from the engine through the coolant into the air in the cab.
HOLY SHIT !! Lmbo i do hvac by trade ben doing it for 25+ years. Hahah you know what you’re talking about . Haha im a chiller plant engineer now but that’s a good explanation you did there.
Cool to watch a guy go through this stuff without a script. Also I know you’re from Long Island. My dad raced on Long Island throughout the 70’s with a guy named Vinny Crawford. Had a 69 Camaro, Vega, 2 monzas and a late 70’s Camaro. He raced out of Brooklyn mainly but lived on out in Long Island briefly. Thanks again for the great content.
Learned the lesson about the compressor oil the hard way! Bought a "134A conversion kit" and installed it myself... The pump locked up solid, ate the serpentine belt, that spun the alternator, that blew out the digital dash! After that I took it to a air conditioner "expert"...
Good video, Tony! If you take an older car to a shop that specializes in A/C work, and there's a ton of them here in Arizona, any decent tech is going to place the system under vacuum and see if it holds that vacuum. If it doesn't, they're going to let you know that the system will leak and give you a price, probably a hefty one, for diagnosis and repair. Some won't even fill the system if it's leaking. Also, many cans of refrigerant you buy now has oil in it and there are retrofit kits to go from R12 to R134 without replacing lots of parts. They work, I've used them more than once. Buy the can with the gauge on it and fill it yourself. Sure, it may not work as good as it could, and it may leak down in a few months or a few years, but it didn't cost you a couple of grand to get it to blow cold either.
@@haywoodyoudome depends on the vehicle. some cars you could take the whole dash out in 7 bolts abd a few wire connectors. most gm evaps come out from under the hood.
That was great! Thanks for sharing! I had to figure it all out myself when I put 86 Dodge truck under-hood components in my 74 Duster with Factory AC. I bought it with no under-hood parts.
Excellent presentation UT! Can those old compressors be overhauled if totally shot? If so, how ‘bout a vid covering that topic, and one explaining what it takes to convert this things to accept today’s refrigerants?
"Freon" is a trademark for a group of refrigerants. The Freon brand name covers R-12, R-22 and several other refrigerants. Anything used in an AC system is a refrigerant. Used in a spray can it's a propellant.
the other reason to not just charge it, if its empty now, it went somewhere. New refrigerant is just going to go away again if the leak isn't fixed. Most of these old systems leak at least a bit but after decades the O rings and gaskets are usually shot and need to be replaced.
@@mr.gutwrenchTo be a 2 stroke compressor is not the same as being a 2 stroke combustion engine. I would just gear a cam to it [dual overhead cams] and then decide if I wanted to make it a 2 stroke or not. It would be possible with a roots blower to make it a 2 stroke, but without positive air displacement you can't make a 2 stroke, and you can't use its block as a displacer port because it has 2 offset pistons into one chamber. Also the compression ratio would undeniably change because you need room for the valves on top. There's little chance it would even be 12:1 by the time you put a set of heads on it unless you domed the piston and made it a HEMI. I would go for diesel, except that diesel engines lose a lot of their efficiency when you drop their burn time using such a short travel and high rotational speed. I'd probably run it on a mix of methanol and nitromethane.
I used to drive a '67 Swinger. It came with 4/60 factory air - roll all 4 windows down and go at least 60 mph! Also, I remember a convertible Swinger was made; I wonder how many were made and how popular they were?
Cool . Hold the system under vacuum overnight and that drier is good as new. All the moisture is gone. Used to use an electric vacuum pump and just left it plugged in overnight.
Hee, it's nice to see you go through the quirks of AC that age. In cars that old it just wasn't a common option people went for back in Boston, and us kids would just rip it out if it didn't work, or sometimes if it did, cause it was sucking power and adding a lot of weight. :) (I think if I did really want an AC in something that old, I suppose I'd spring for one of those modern aftermarket systems that are smaller and simpler and less of a parasitic loss.) I never actually *fixed* an AC system till I came down here. (And I actually simply took it all out of my Volvo cause my blistering 115 horsepower just calls for more lightness anyway. :) )
I hope you include the AC repairs that will be done as content. I've heard most common leak on Mopars is the compressor seal, I would love a seal repair video.
The crankcase seal is lubricated by the oil in the compressor/system. Turning your A/C on for a few minutes every time you turn on your engine will lubricate these seals. Once the seal dries out it gets brittle and shrinks up and you lose the refrigerant.
I am retrofitting AC into my Valiant using the controls & box from a '75. The compressor is a later Sanden, brackets & pulleys. from a later LA. Got a new condensor, evaporator, box parts, dryer, lines & all from Auto Air Solutions. People might say, "I'd never add AC; adds weight, complexity, isn't original..." but I live in the South and would like to drive my cars whenever, the added weight can be offset by lightening things up, moving the battery to the trunk, et cetera, and not to mention I don't own "Museum pieces"
Something the old mopars had that all of folks did not know is they have a cycling switch in the dark abyss of the under dash compaction. Also them mopar clutches bite the dust it seems. Also a tid bit the large A/C line is a 3/4" tube. However to have new lines made with barrier hose the fitting is a 5/8" so no big deal, just make the cut.
Thanks for this, a lot of people today need this type of info. And we love ya but..bit... Decadent is something luxurious, "desiccant" absorbs moisture. 😉
When younger I wouldnt consider buy mopars with AC. If I saw that big thing on the front of the engine and was afraid of it :P. Little that I know it was just a compressor. Greetings from Holland
I cannot thank you enough for helping me learn these things, I don't have anyone in my area that knows jack shit or if they do, they're usually an asshole and usually work with newer cars. So thank you, thank you thank you!
Im not sure about all makes/models. But my 1980-1991 ford trucks I love tinkering with, they don't have a heater control valve. I always install a manual valve to cut off that extra heat around the evap core.
Tony, about your quick comment about the valve that shuts off the coolant to the heater core. On Ford, the coolant runs continuously through the heater core. An addition I found helps the A/C it to add a shut off valve in the coolant line going to the heater. Just a ball valve from a plumbing supply store. That way, the heater and A/C are not fighting each other. The only caveat is that to prevent corrosion, open the valve one day every now and then (I do it the first of the month) just to get fresh coolant in the heater core.
The orifice tube on my 93 GM pickup is located right at the outlet of the condenser. I thought that was a strange design. Perhaps it doesn't matter whether you have high pressure refrigerant or low pressure, cold refrigerant running back to the firewall.. it's going to absorb engine compartment heat all the same.
I have a stock RV2 on my early 80 D150. The later ones seem to have Sankyos which are much lighter. I have to use my cherry picker to pick up and install that late 50's design RV2 because at 70 it kills my lower back for days. Works great but even with aluminum heads it's a heavy mother!
This is the kind of content you had on TV before everything got dumbed down
I haven't watched cable tv in close to 20 years. No news, or even the weather in about 10 lol.
I'm in my early 30s too, got tired of the bs a long time ago, aspecially the news, it makes you depressed seems like.
I go outside and do stuff, love me some youtube automotive videos though 😄 it's good for ya
TV automotive shows Lost touch with reality years ago..
Sponsor's agenda is king
Yea missed the old days on TNN with the outdoors shows and then car shows.
@@motov8-garage832same here. I'm in my late 30s and tv is nothing these days. Used for video games once in a while. The news was only watched for the weather toward the end of my TV days
I'm a retired mechanic and you did a great job explaining the AC system. I specially love the explanation of the dash. Hilarious!
Good job.
I'm an ASE certified mechanic of 30 years.
People in my town are amazed that the AC works on my 78 f100 farm truck. They can't get there 5 year old vehicle to blow cold air.....
Same here. 76 Dodge Dart all original and the AC still blows ice cold.
UTG covers so much so clearly and quickly; a 15 minute video has 30 minutes of information.
You nailed it. Awesome video. Compressors don’t die they are killed. Your failing expansion valve is what killed your compressor by not regulating refrigerant flow properly the compressor wasn’t getting enough oil and seized. Don’t replace a compressor without figuring out why it died or else you’ll be doing it twice. I’m a refrigeration guy 👍🏻
The question has always been, "when does a vapor pump turn into a liquid pump?" Just before you replace it.
We had a pererbilt eat 3 last summer.
I got blamed for the backwards orifice when the second one I did died.
I pulled it out with needle nose pliers, held the new one beside the old to grab it so I'd get it the right way.
That truck ate one every spring.
I've been working on automotive ac systems for over 30 years and you did a wonderful job explaining it's workings Uncle Tony!
I got a good chuckle out of it...
Between 'decadent' and 'the closest thing to hell while still being alive' comments, it was great!
I no longer believe A/C to be magic!
Uncle Tony explained how it works, excellently.
My dad was an engineer for Harrison Radiator Division, General Motors Corporation. How did I not know the workings of an A/C unit?!?!!
Some of the old style compressors are able to be used as an auxiliary air compressor. Since they store oil in a sump rather than relying on oil flowing in the system they will work fine without a closed loop system. Can be super handy having an engine driven air compressor with an electric clutch.
Again, UTG is the best thing going on the internet.
Your knowledge is a national treasure for us younger folk
Orange on muscle cars is Always class! Love that color
I've been messing around working on my own AC for 30yrs and can usually make things work "pretty good", you easily doubled my grasp of the system with 1 video. My Dad spent 40yrs as a Chrysler tech and he explained this to me a dozen times but never in a way that really came together into a complete picture in my(feeble) brain. He's 86 and I'm doing most of the work on his Dakota daily and '79 HotRod Pick-M-Up these days, I'm going to sound like less of a rookie next time I work on his AC.
Thanks Tony
Love this kind of content. Currently trying to become comfortable w ac systems so I can repair them in my classics. Would drive them way more with working ac
Tony, Thank You for another video for we folks who are not racers but only want a solid daily driver!
RRRRooooooLLL up Your Windowwws, damn it! The Air Conditioning is on!!!!
Youve given great advice; but for those people who choose to do it themselves (with an R12 such as the 72 has), please do not use butane as a substitute for r12.
Until my retirement, i checked what type gas was in the system of EVERY a/c system i worked on. You never know what is in it! You'd be surprised as to what is in some of these vehicles.
Also, for those considering doing a conversion from r12 to r134a, be advised that r134a is far less efficient at cooling and takes a lot longer to cool down a vehicle. I did conversions on a European import make when the factory offered a conversion gas kit and not one customer was happy with the results.
Finally, if the vehicle is more than 5 years old, i replaced the schrader valves as a part of a normal recharge, thus avoiding a potential comeback from a work valve.
Enjoy your videos, keep it up.
The effective replacement for R-12 what I’ve been told is R-152 which is the compressed air in a can for blowing dust out of your desktop keyboard. You throw about x2 the weight of r-12 n it does the same thing. Better than r-134 conversion
@@jayslpstapes519that's what I've heard as well. R-152a and under half the weight as factory R-12 charge for the system to run well. It's slightly flammable but nowhere near as much as butane propane mix. It also happens to be 10x better for the environment than R134a and infinitely better than R-12. I suspect 152a will be making a comeback now that our global warming potential for new refrigerant systems needs to get under 700 by 2025.
R32 is 675, barely making the cut. R134a is 2000 ish, r152a is 170. Propane is like 3.
I watched this and thought Tony did a great job explaining for someone who isn't experienced with A/C. I knew the comments were gonna be full of scientists who just have to display their knowledge on thermodynamics and how a/c systems work. It's like every video he makes everyone has to correct and critique when they miss who the videos are even made for
I've always favored the txv (thermostatic expansion valve) system with the receiver drier over the orifice tube and accumulator drier on the suction line. They are WAY easier to add a little charge to if the system is low via the sight glass vs having to pull the charge and weigh in the correct amount on an orifice tube system. Anything else on an orifice tube system and you're just guessing. The other thing nice about a txv system is it can react to different operating conditions and meter refrigerant accordingly. As a former transport refrigeration and air conditioning mechanic of many years I think you did a great job explaining the system!
Great job Tony, I'm 609 certified and you lay it out easy, awesome man
Thank you Tony 🙂👏👏👏
Just to clarify. The compressor compresses the freon into a high pressure gas. 300+ psi inside the compressor, 200ish in the high side line. That generates a tremendous amount of heat, over and above what you are actually trying to remove. The evaporator is the first stage of the system, where the heat is absorbed. The condenser is the last stage, where heat is transferred to the outside world.
The compressor does not force the freon to turn into a liquid. When the hot gaseous freon gets to the condenser, it is cooled by the air going over the condenser and condenses the freon into a liquid from removal of heat and a slight pressure drop across the condenser. Then it is off to the expansion valve, orifice tube, or POA valve (pressure over atmosphere). This is exactly why some systems have 3 service fittings, high, low, and an aux/liquid port to check the pressure drop thru the condenser.
The cooling does not happen in a valve, that is a longstanding myth. The cooling is from the freon boiling in the expansive volume of the evaporator. Freon starts boiling anywhere from -45 to 5 degrees depending on the type. The freon changing from a liquid, by boiling off in the evaporator, is where the cooling actually occurs, by absorbing heat. I never saw a pot of water instantly boil off, neither does freon. You can literally pour some types of freon on the floor, then it boils and it only boils at the surface of the puddle/droplets... There are refrigerants that can sublimate, and they are not used in cars. Sublimate means it skips the boiling stage during expansion, and instantly turns into a gas. Those are used to get to very low temperatures in manufacturing and storage.
A receiver dryer is always on the high side of the system, and an accumulator is always on the low side, if they are equipped. Some systems have one or the other, some have both. Neither are disposal at every service because the moisture can be removed easily with a vacuum pump and a heat source. Water boils at 72 degrees in a 29" vacuum. And that is how you get the water out of them, apply a vacuum to the system and if needed apply heat to the desiccant.. If you have a compressor failure, or mixed refrigerants or oils, then that is a completely different issue, and either of the two are the least of your problems because far more needs replaced....
People replace dryers/accumulators to save time, because they want a far shorter vacuum cycle. Time is money, kind of thing.... Not because it is a disposable part once the system is opened.....
I taught this, for nearly 35 years...... Most people don't understand how ac actually works. You cant make cold, but you can remove heat.....
This explanation, exactly. Tony’s explanation is fine from a practical sense when understanding how to swap parts to make things work but there are a lot of inaccuracies in his explanation of how the system actually works. Once it clicks for you how it works it makes so much sense. I think of it like this and correct me if I’m wrong. Cool low pressure liquid to evaporator, which makes cool low pressure gas to the compressor which makes hot high pressure gas to the condenser which makes hot high pressure liquid to the expansion valve or orfice tube (etc) which makes cool low pressure liquid to the evaporator. That’s the whole thing in a nutshell. It’s the boiling and condensing (latent heat/phase change) that moves the heat from one place to another. Evaporator takes heat from the inside air to boil the refrigerant. Condenser sheds heat to the outside air to condense the refrigerant. Thus the system moves heat from inside to outside. So simple.
@@gatesj777 You understand it better than most people.
Thank you great explanation. Is it true that it's helpful to run the A/C occasionally during off season to circulate the lubricant? I repaired my 1965 Ford A/C in 2012 and it still blows ice cold - every week or so I turn the A/C on for a few seconds hoping it helps.
@@garyspaun5237 In most cars it runs with the defroster, so you technically use it all year anyway.
a good explanation there, I remember a course I did way back in HVAC days when the Vapour Compression Cycle and the Latent Heat Change was first explained to me, once you understand the physics behind it, the penny drops.
This has to be in your top 10 ...
Maybe even top 5...you're really good at explaining how things work...in simple terms...thank you...
I think Tony meant desiccant not decadent.
When he said that I just pictured a tiny Roman emperor inside the accumulator being fanned with a leaf and fed grapes.
@@michaellehmann2803😂😂😂 that's decadent for sure. I'm thinking John Belushi in a toga with a laurel wreath.
Just made me think of chocolate, I didn't get any Roman emperor toga visuals.
I remember the first car we had with air conditioning. We drove it when it was new, up to Canada in the Summer for the World's Fair. It was so humid, the air conditioning was dripping waitron in the passenger side floor. We went to a garage where they spoke French, they told us it was normal and that the humidity was overwhelming the air conditioning drain. All of the garage technicians at the garage in Canada wore white doctor coats. After Canada, the A/C drain was never a problem again. The owner's manual said to run the A/C at least once a month, even Winter, for certain number of miles, to keep it lubricated and from seizing up. It didn't cycle with the defroster, like they do in newer cars, but mentioned using the A/C to defog the windshield. We had the car for 10 years and the A/C only lasted for about 5 years., but with quite a few miles on it.
If you are working on an old Mopar and you find a valve inside the compressor where the low side hose attaches take it out and throw it away. It's called an Evaporator Pressure Regulator (EPR) valve and they must have been trying to outdo Ford for better ideas the day they came up with that one. It served no good purpose and did nothing except malfunction when you least need it to, like on the way to a wedding or a funeral. It was supposed to help keep the evaporator from freezing. Love your channel, Tony. It reminds me of those days in the garage when going home looking like a grease monkey and with genuine busted knuckles were everyday realities working on those old cars.
Always liked the Airtemp cast iron v twin ac compressor, it ran flawlessly in my 1971 Newport for the 14 years I’ve owned it.
Good job explaining this Tony, and covering all areas. Strange as it may be, our first local Mopar down under with factory integrated air, was in 1969. In 68 you could get a dealer fit under dash system. In 1970, the system was changed to run a Tecumseh parallel twin compressor, so that V twin died off here. Good work. Highly regulated down here, no such thing as home charging, has to be done by a licensed operator, and they know how to charge!
We forgot the theory, change of state is critical, we also have heat transfer from condenser and evaporator, txv and orifice tube operation, as in change of state, ALSO the refrigerant carries properties such as a direct pressure to temperature relationship..
I agree, but he didn't do badly for a 15-minute primer.
Good job Tony
You hit all the points. That’s coming from a supermarket refrigeration mechanic.
I’m on the north side of 50 and I’d never fully understood the a/c system before. I’d heard the terms for things but never had a complete run through of what happens in a a/c system. I’m not to proud to admit I ‘rewound’ this video acouple times to listen to how you described some points a second time.
I remember years ago going through an AC class and didnt remember a thing and got the certificate. Was it the class or me I dont know but probably both. I learned more in this video than that class so thank you
Really good to undestand basics of A/C on older cars, also I see most of the old stuff still make it's way into newer cars aswell!
If possible, make a video on the differences from a carb that has the A/C stuff and one who doesn't, I think there's some parts needed on those carbs, I'm not 100% sure. Great video as always Uncle Tony!!!
its usually an electronic solinoid that extendes to raise the idle speed with the ac on so the load of the compressor doesent stall out the engine.
You remind me of my Dad. A Chrysler guy thru and thru. Owned his shop 42 years.
Replacing the "dryer" is kind of an outdated thought from when people may not have fully understood the systems and/or vacuum charging wasn't as common. When you pull a vacuum on the system, you're not just evacuating it of air, you're boiling the water out. Just like how a pressurized cooling system increases the boiling point of water, vacuum decreases it. On a nice hot day, with a consumer grade vacuum pump (mine is a lower end Robinaire... not that different from the HFT ones), you can generate enough vacuum to boil the water at ambient temperature (from memory... I think this is around 90F at 29 inches of vacuum... so... the hottest day of the year is a good time for A/C work 😆). When you boil the water, you're boiling it out of the desiccant too and "recharging" it. Also... If you do buy a new dryer, it's not like they come sealed. The last one I did replace just came with plastic caps over the fittings so the threads didn't get damaged. New ones need vacuumed down too... and usually need some amount of oil added to them before installation.
Where you _do_ want to replace your dryer/receiver/accumulator is when you have a catastrophic compressor failure or the system has been open for a long time. Running the risk of pumping tiny bits of debris out of one into a new compressor isn't worth the few dollars it saves. I wouldn't bother to do it for something like an o-ring failure on a recently working system though. Fix the leak, vac it down, charge it, send it.
Good video, you should be an autoshop teacher. AC and 5 speed were the best things I ever put in my 66 Chevelle. I got ac licenses years ago, but quit working on them myself except for emergencies.
Why did you stop? What made you want to stop?
"The closest thing you can come to hell without actually being dead is under the dashboard of an air conditioned classic car" 11:14
I am a commercial/industrial A/C technician and did a retrofit on my friends 1964 Thunderbird. Zen state all the way in the interior.
Excellent video and explanation Tony. I have recently installed Vintage Air in my 55 Chevy 2dr sedan. It was a big project but well worth the effort.
So helpful! Thank you so much for going over how the basics of the A/C system works. I recently purchased a ‘66 Impala sedan with factory installed A/C (still looks like it has the factory-installed compressor in it because I can still see the remnants of the Frigidaire sticker on it) and have been trying to figure out what to do to get it back in functional order. Your explanation helped out a TON!
Back when I was younger and didn't have to nickels to rub together I used propane as my refrigerant every now and then. I don't recommend anyone doing that, but it works. Just got to remember and realize you have a ticking time bomb under the hood and dash of your truck/car. Propane or not I highly recommend a fire extinguisher in any vehicle new or old, it may save you or someone else car from going up in flames.
The Dart has what's called a Thermal Expansion Valve or TXV for short. Most systems now use an expansion valve instead of the orifice tube. The new expansion valves regulate off of pressure/volume alone.
Derek ,hell of a mechanic ,and more ,Dan from DD rock on brother ,,Uncle Tony is the real Deal Holyfield and probably forgot more than most people know , imagine being able to educate just off the top of your head , CHEECHIN MINT !!!!! JUST A DOWN TO EARTH DUDE , UTG RULES !!!
I was working in the hellish under dash today. Getting closer to having working angel breath.
Learned something new today, thank you UTG 😊
My favorite episode yet. Thanks for really explaining the system in detail. Keep up the great content!
Thanks Uncle Tony for making this video, it was sorely needed! I, like many others just needed the shop teacher breakdown of what everything is and does, especially the valves and lines up close to the firewall. Keep the Chrysler guru knowledge flowing!
Great video Uncle Tony. This is the type of content that I came to your channel for to begin with. Thanx!
Pretty good explanation with the exception of you aren't compressing liquid as that's not feasible and the condenser is converting that gas into liquid there. But I'm sure you helped some people understand better. 👍
Ty for this vid man , you're a worker . You explained this very well and helped me as I'm apartment maintenace and just learning this stuff . With the ol super heat n sub cool stuff . Piston / orfice vs Txv type and latent vs sensible measured saturation change etc
These kinds videos are the reason I started watching you and quickly subscribed ! Soup to nuts common sense explanations that make sense at least to people that want to fix their own stuff !
Good info. I had some rental properties in Georgia and all had heat pumps so to save money I took a HVAC course and watched a few TH-cam videos which allowed me to successfully install and maintain the systems. I live in the Philippines now and brought all my HVAC tools and vacuum pump since I had to install 4 mini splits on the house we had built. The Filipino installers don't use vacuum pumps. I bought a 2002 Suzuki Carry mini truck that has a 660 cc 3 cylinder engine. The A/C lost the charge a few days after I bought it. There was an o-ring leaking so I replaced all o-rings pulled a good vacuum and recharged with R134a and it is ice cold in the tiny cab. I also added an ounce of oil for good measure. It is cool because the condenser isn't in front of the radiator, it is beside the radiator and both have electric fans.
I'll never forget watching someone at a local garage adding a can to a system. Is it blowing cold yet he asked another guy in the car. No he said so they go for can number 2. All of a sudden it sounded like an M-80 went off under the hood. Another guy thought the battery blew up. Turns out a pressure line blew. Maybe one of you AC guys could explain what happened. After seeing that I never tried to recharge a system myself
really enjoyed the content. Love to understand how things work and Thanks for explaining in easy to understand but detailed way.
Finally got my AC working in my 94 ranger. First old car with ice cold air. Was a puzzle, last owner removed parts and I had no idea.
I like this car, 👌 I rember when Tony painted it, and dropped the 360 in it, it was built as the basic "daily driver" .
An A/C system is just a heat exchanger. The pressure drop through the expansion valve turns it to a gas which makes it low pressure which makes it cooler than the ambient air. As the freon in a gas state passes through the evaporator it is removing heat (energy) from the cab by absorbing it into the freon. The reason the freons temp rises so much after being compressed is from the heat (energy) that it removed from the cab being compressed to a much smaller area, it concentrates the heat. Most of the heat coming off of the condenser is concentrated heat from inside the cab. It's removing the heat from inside and releasing it outside therefore leaving the air inside cooler. Hot air is energetic air. When using the heat you are transferring energy made from the engine through the coolant into the air in the cab.
You nailed it!
Tony did not...
Some good tech in this one. I've always thrown that crap in the shed and gone my merry way but it might be time to re-consider.
HOLY SHIT !! Lmbo i do hvac by trade ben doing it for 25+ years. Hahah you know what you’re talking about . Haha im a chiller plant engineer now but that’s a good explanation you did there.
Cool to watch a guy go through this stuff without a script. Also I know you’re from Long Island. My dad raced on Long Island throughout the 70’s with a guy named Vinny Crawford. Had a 69 Camaro, Vega, 2 monzas and a late 70’s Camaro. He raced out of Brooklyn mainly but lived on out in Long Island briefly. Thanks again for the great content.
Learned the lesson about the compressor oil the hard way!
Bought a "134A conversion kit" and installed it myself...
The pump locked up solid, ate the serpentine belt, that spun the alternator, that blew out the digital dash!
After that I took it to a air conditioner "expert"...
Good video, Tony! If you take an older car to a shop that specializes in A/C work, and there's a ton of them here in Arizona, any decent tech is going to place the system under vacuum and see if it holds that vacuum. If it doesn't, they're going to let you know that the system will leak and give you a price, probably a hefty one, for diagnosis and repair. Some won't even fill the system if it's leaking. Also, many cans of refrigerant you buy now has oil in it and there are retrofit kits to go from R12 to R134 without replacing lots of parts. They work, I've used them more than once. Buy the can with the gauge on it and fill it yourself. Sure, it may not work as good as it could, and it may leak down in a few months or a few years, but it didn't cost you a couple of grand to get it to blow cold either.
I'd still recommend getting a two gauge manifold as they can tell you a whole lot more about the system than those single gauge fillers can.
And purge the lines before you pop em down.
Evaporator replacement PTSD is a real thing. Great vid UTG
Blown head gasket - no problem
Blown rear main seal - easy
Needs a new evaporator - time to put it up for sale
@@haywoodyoudome depends on the vehicle. some cars you could take the whole dash out in 7 bolts abd a few wire connectors. most gm evaps come out from under the hood.
@@richardcranium5839 mid to late 80s Mitsubishi Starion, late 80s Tbird and Cat and John deere heavy equipment. Being a contortionist is an asset.
Great video. Exactly what I needed. Greatly appreciated. My desiccant is probably also decadent.
Classic Auto Air is a good source for old system components
That was great! Thanks for sharing! I had to figure it all out myself when I put 86 Dodge truck under-hood components in my 74 Duster with Factory AC. I bought it with no under-hood parts.
Excellent presentation UT! Can those old compressors be overhauled if totally shot? If so, how ‘bout a vid covering that topic, and one explaining what it takes to convert this things to accept today’s refrigerants?
Great explanation. I have a general knowledge of the components but not necessarily how they worked together
Nice job Tony.
"Freon" is a trademark for a group of refrigerants. The Freon brand name covers R-12, R-22 and several other refrigerants. Anything used in an AC system is a refrigerant. Used in a spray can it's a propellant.
the other reason to not just charge it, if its empty now, it went somewhere. New refrigerant is just going to go away again if the leak isn't fixed. Most of these old systems leak at least a bit but after decades the O rings and gaskets are usually shot and need to be replaced.
I often thought about taking one of those V-2's and making a tiny motor out of it.
Just never got around to it.
It would be cool though.
@@mr.gutwrenchTo be a 2 stroke compressor is not the same as being a 2 stroke combustion engine.
I would just gear a cam to it [dual overhead cams] and then decide if I wanted to make it a 2 stroke or not.
It would be possible with a roots blower to make it a 2 stroke, but without positive air displacement you can't make a 2 stroke, and you can't use its block as a displacer port because it has 2 offset pistons into one chamber.
Also the compression ratio would undeniably change because you need room for the valves on top.
There's little chance it would even be 12:1 by the time you put a set of heads on it unless you domed the piston and made it a HEMI.
I would go for diesel, except that diesel engines lose a lot of their efficiency when you drop their burn time using such a short travel and high rotational speed.
I'd probably run it on a mix of methanol and nitromethane.
I used to drive a '67 Swinger. It came with 4/60 factory air - roll all 4 windows down and go at least 60 mph!
Also, I remember a convertible Swinger was made; I wonder how many were made and how popular they were?
Cool . Hold the system under vacuum overnight and that drier is good as new. All the moisture is gone. Used to use an electric vacuum pump and just left it plugged in overnight.
Hee, it's nice to see you go through the quirks of AC that age. In cars that old it just wasn't a common option people went for back in Boston, and us kids would just rip it out if it didn't work, or sometimes if it did, cause it was sucking power and adding a lot of weight. :) (I think if I did really want an AC in something that old, I suppose I'd spring for one of those modern aftermarket systems that are smaller and simpler and less of a parasitic loss.)
I never actually *fixed* an AC system till I came down here. (And I actually simply took it all out of my Volvo cause my blistering 115 horsepower just calls for more lightness anyway. :) )
I hope you include the AC repairs that will be done as content. I've heard most common leak on Mopars is the compressor seal, I would love a seal repair video.
The crankcase seal is lubricated by the oil in the compressor/system. Turning your A/C on for a few minutes every time you turn on your engine will lubricate these seals. Once the seal dries out it gets brittle and shrinks up and you lose the refrigerant.
I love your videos Tony. Always explained very well. Keep them coming.
Dude, your videos are essential. This one may land me into a cool ride with my Olds:)
Very educational Uncle Tony. Thank you!!
Great job uncle Tony. Well explained.
I am retrofitting AC into my Valiant using the controls & box from a '75. The compressor is a later Sanden, brackets & pulleys. from a later LA. Got a new condensor, evaporator, box parts, dryer, lines & all from Auto Air Solutions.
People might say, "I'd never add AC; adds weight, complexity, isn't original..." but I live in the South and would like to drive my cars whenever, the added weight can be offset by lightening things up, moving the battery to the trunk, et cetera, and not to mention I don't own "Museum pieces"
Something the old mopars had that all of folks did not know is they have a cycling switch in the dark abyss of the under dash compaction. Also them mopar clutches bite the dust it seems. Also a tid bit the large A/C line is a 3/4" tube. However to have new lines made with barrier hose the fitting is a 5/8" so no big deal, just make the cut.
People think that anything that they don’t understand should be removed: evaporative emissions, a/c, etc.
Thanks for this, a lot of people today need this type of info. And we love ya but..bit... Decadent is something luxurious, "desiccant" absorbs moisture. 😉
Good stuff Uncle Tony…I need some of that decadent desiccant 😊
When younger I wouldnt consider buy mopars with AC. If I saw that big thing on the front of the engine and was afraid of it :P. Little that I know it was just a compressor.
Greetings from Holland
Your right I can build a small block Chevy blindfolded but I'm lost with an ac system
I cannot thank you enough for helping me learn these things, I don't have anyone in my area that knows jack shit or if they do, they're usually an asshole and usually work with newer cars. So thank you, thank you thank you!
Thanks. This is the one I was waiting for.
Strange, the other Mopar guy did an A-body A/C video earlier the same day as this one.
Im not sure about all makes/models. But my 1980-1991 ford trucks I love tinkering with, they don't have a heater control valve. I always install a manual valve to cut off that extra heat around the evap core.
Good stuff Tony. Now, would you please explain, in-depth, the Mopar ATC and ATC II systems? I'll grab the popcorn...
Tony, about your quick comment about the valve that shuts off the coolant to the heater core. On Ford, the coolant runs continuously through the heater core. An addition I found helps the A/C it to add a shut off valve in the coolant line going to the heater. Just a ball valve from a plumbing supply store. That way, the heater and A/C are not fighting each other. The only caveat is that to prevent corrosion, open the valve one day every now and then (I do it the first of the month) just to get fresh coolant in the heater core.
R12 Freon is illegal in the State of California. But if you cross the Border they have plenty. Great Content UTG . From San Diego. 👍
Hey Unc that was informative, thank you! Now how about a repair the Duster AC system video?
Very well explained UT. Thank you.
The orifice tube on my 93 GM pickup is located right at the outlet of the condenser. I thought that was a strange design.
Perhaps it doesn't matter whether you have high pressure refrigerant or low pressure, cold refrigerant running back to the firewall.. it's going to absorb engine compartment heat all the same.
Thank you Tony.
Great tech session again!
I have a stock RV2 on my early 80 D150. The later ones seem to have Sankyos which are much lighter. I have to use my cherry picker to pick up and install that late 50's design RV2 because at 70 it kills my lower back for days. Works great but even with aluminum heads it's a heavy mother!
I’m watching this video in my car, with fogged up windows, because it’s raining and my AC doesn’t work.
Nice job!