The GM CCOT Air Conditioning Sytem Was One of the Best!
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- Опубліковано 28 сер 2024
- In this video, I'll be talking about what I think is one of the best air conditioning systems GM used in the 80s and 90s: The cycling Clutch Orifice Tube system, full of R-12 Freon.
As a 53-year-old man, I can still remember the magic of R12. I remember when I did R134 conversions in the 1990s, you could feel the difference in your hand. I can remember being a kid in the early 1980s, and my grandma and grandpa having a Chevy Caprice that you could freeze yourself out on the hottest summer days. They lived in an old farmhouse that did not have air conditioning. So on the hottest days, they would find a reason to go out and run errands. Think about it. On the hottest days of summer when people were hiding inside, they would go get in their car and go drive around because that AC was cold enough to hang meat
Facts!
My grandparents had GM sedans in the '80's and those AC systems were ice cold!
All my r134 cars have 35*f vent temps. How much colder do ya need?
@@cptbuiltk7944 I have both R134 cars and a R12 car. The difference is instantly noticeable. The R12 is far superior. Cools very fast and it stays cold in the car at much lower settings than my R134 cars. None of my R134 cars can compete with R12.
@cptbuiltk7944 Well, I don't know quite what to say since I'm not sure you grasped my comment. Later R134 systems could cool quite well. If you care to remember from my comment, I was talking about that gray area in the 1990s where we did conversions. You see, R134 is not as efficient as R12. It's not as good at moving heat. It needed a different system with higher high side pressures, and was far less forgiving on compressors. The very best and most modern air conditioning systems still take a moment to get going, so to speak, but if you had a properly functioning R12 system, you could turn the key and kick that bad boy to max cool. Like I said, the later technology caught up, and a properly running R134 system can do its job. But nothing moves heat as efficiently as R12.
I've still got a case of new R12 cans in storage :)
You just explained the basic operation of all automotive air conditioning. GM’s high capacity compressors is what gave them the advantage in the late ‘60s to the early ‘80s, mainly the A6.
The Frigidaire A6 compressor was a BEAST!!!
Freakin blowin snow out the dash vents 😮
But also put a hell of a load on the engine...
Yes, the A6 compressor may have been big, heavy, and required a lot of hp to run, but it was virtually indestructible. If you did get liquid into it, it would lock up and break the belt rather than damage the compressor. But those "tuna can" Harrison compressors were junk.
You are right sir
@@marko7843you are right but I had a 500 cubic inch V8 pushing it lol so it wasn't really a problem ,👍🔥🔥🔥💪💪💪
I have a 1993 Buick Century Special that I have owned since new. It still has it's original factory charge of R12 in it and it is ice cold.
Lots of poor life choices eh?
@@cptbuiltk7944why is it a poor life choice to have an older car since new? Some people aren’t materialistic, and don’t need to buy the newest stuff. New stuff doesn’t make you better or mean you have more money than anyone else. You’re not better than anyone else either because you have something newer or better. Don’t always judge a book by its cover.
Who said that's his only car?@@cptbuiltk7944
pretty solid A-body car
What was once a depreciating asset is now an appreciating asset
Making it really simple , the orifice tube is like a spray can tip.
Take a spray can and blast it till its empty.
It got cold ,right?
Move some air across that cold can, voila theres your AC.
Now the fun part is learning how you suck up heat in one thing (evaporater) and spit it into another to get rid of it (condenser)
Latent heat and all that jazz.
Ac theory is ,well, pretty freakin cool! 😬
I had a 1981 Camaro with CCOT and A6 compressor - AC was always cold. My wife had a 1977 Mercury Monarch with the 302 V8 - it had a "Motorcraft" labeled A6 compressor. The Monarch had ice cold AC as well. GM's Frigidaire/Delco division air conditioning components were used everywhere back in those days.
On Rolls Royce and Mercedes as well!
1984 Chevrolet S10 Blazer 4 Wheel ice ice Cube A/C. I mean Make your Nipples Hard, Loved it when girlfriend now Wife Was in the Blazer. Back in The Day...😜
@@Ascotman I remember looking at a Mercedes 450SL. It had a GM automatic transmission, and a GM A6 compressor under the hood. The passenger compartment wasn't large at all, so that huge A6 compressor was complete overkill for that car!
Yep nobody else pretty much had the capacity of a A6, and they also used less hp than many of the inferior compressors
@@audvidgeekI always found it interesting to see European cars get automatic transmissions and air conditioners from other countries back then, whereas many Japanese companies built their own.
Yep we had a Caprice Classic which blew freezing cold air conditioning and even our much newer Oldsmobile Aurora has super cold air conditioning. My Corolla I had years ago had very cold AC as well and I believe it's Denso components on it but man was the car slow to accelerate when the AC was on.
The reason many old cars have lower airflow is due to the evaporators being plugged up with all manner of schmag in the time before cabin air filters became common. Leaves, pine needles, cottonwood seeds, dirt, etc.
My 72 Chevy truck even running a Sanden retrofit compressor but still using the POA system (R12) and it is cold as hell! Can’t beat these old systems. Period.
The thing I liked most about 112 was that it was so forgiving. When we were kids we couldn't afford hoses and evacuation pump. We added refrigerant until the AC got cold. Hell if we needed parts we went to the junk yard. Times have certainly changed.
It's true. 1980 Malibu Classic with a 229 with CCOT using an A-6 Compressor. It was *COLD*. The R-4 compressor was ok, but the Axial A-6 (the long compressor) was the best.
Frigidaire engineers were experts with decades of refrigeration experience. Even Rolls Royce used to buy from them
I have a 92 Miata that still has its non converted R12 system. Got lucky and found an old cylinder of R12, I think its a 15-20Lb. Then my old boss gave me 2 gas grill size recovery containers that are also full of R12, ill probably sell the two recovery containers to a refrigerant recycler as I hear they're worth a fortune and keep the new stuff to keep the Miata running.
In my 1971 Oldsmobile I’m running an aluminum body a6 with the newer style clutch and swapped the poa valve out for an orifice tube with a pressure switch on it to cycle the clutch. Using a huge modern style condenser rather than the old tube and fin. R134a in it. So it operates like this system but still uses the a6. The original a6 clutch won’t hold up to the cycling rate that this system uses so it’s gotta have that new style clutch. Drove it out to the desert in 110 degree heat and was getting 40 degree air at the vents still 😁
Me and my dad driving around Lake Havasu CIty AZ in my 85 Monte Carlo, it was 120 degrees that day and my dad leans over and says "can you turn that a/c down a bit?"
When my 77 Chevy C10 still had r-12 in it back in the day it would make the outside of the windows have condensation on them like a coke can. It was a beast of an AC system.
Not much interior to cool
They labeled the high side of the system with low pressure vapor and low pressure liquid. Ooops!!
I have a restored 1972 Camaro SS that still uses R12. I still have a 30lb bottle of R12 I bought at Sams Club for $250 right before it became unavailable to purchase. It has the long A6 compressor and an actual expansion valve. It uses a pressure triggered fuse with a wire coming off the back of the compressor that if the pressure gets too low it will send a signal to the 3 leg fuse to blow it and interrupt the 12V doing to the compressor. It also has the dryer that has a sight glass to check the R12 charge too. It makes it so easy to see if it needs Freon.
Can you tell me where that three legged fuse is located?
Fortunate man
@@HustleMuscleGhias It clips to one of the hoses coming from the charcoal carbon canister on top of the drivers side fender well.
Best car A/C I've experienced: My dear departed 1994 Chrysler LHS. (R134a) This cooled better on low than most cars on max/recirculate. A 1987 Ford LTD I had for a while. (R12) My buddy's old 1972 Chevy Impala that would freeze your ass off. (R12 of course) As far as existing R12 systems, I have a mini Pepsi vending machine from the 1970s that cools great and has never had anything replaced on it that I know of.
My 94 C1500 came with R-134a but the system was pretty much what was in 93 with R-13 just had a different cycling switch and orifice valve. Its so overbuilt it blows cold AC even on 100 degree days unlike any newer vehicle ever can .. ANd it has a mechanical fan. I converted A r-12 to R-134a it works if you are smart with the charge amount. it takes some trial and error. Also the " Dont use" variable orifice valves are good for conversions in my experience. Everyone says to avoid but. good for conversion. Way colder AC at lower speed
The Frigidaire system with the A6 compressor, the suction throttling valve AND a thermostatic expansion valve. Low side pressure at a constant 33 psi, good for sub 40 degree vent temps, that system was the best!
You would open the hood on a steaming hot day, and the return lines all had frost on them! This was mid 60's to early 70's. My '78 with the CCOT never did that, it was designed for fuel fuel economy.
Absolutely correct. The TXV would keep the evaporator at maximum cooling capacity regardless of conditions… 35-40° even in stop and go traffic. Change to CCOT was made for fuel efficiency since compressor cycled .
My 84 C10 still has working A/C. Pancake compressor...it was converted years ago to 134A..but for being as old as it is, it still works well in these California summers...🤙 I love driving around with my windows up blasting the A/C.
It was the R12 that made the difference. I had a 1980 Regal that had vent temps so cold it would numb your face if the air was going straight to it even on a hot and humid day. The condensation from the evaporator would leave huge puddles of water under the car. It was more water than any car I have owned would make meaning it was superior at dehumidifying the air. I also had a 1992 Acura Legend that was on R12. It would cool quickly and vent temp was so cold you had to face the vents away to avoid numbing your skin. If the humidity was over 65-70% and the vent was pushing air on the windows, the glass would cool so fast that condensation would form on the outside and water drops would roll down the glass. R134a feels like it is 85-90% was effective in cooling. Of course, it has been phased out of new cars and will probably be banned from production in the US within 10 years. It used to be $4-5 a can but has more than doubled in price now. Stock up if you plan to keep any car made before 2022 for a while.
I had one of those on my 1978 G 20 van and on my 1977 GMC dually. Both blue ice cold even after I converted them to r 134.
I had a 1988 Chevy Astro van with the R4 compressor. The fan didn't really feel like it moved all that much air, BUT the air coming out the vents would get down to about 38 degrees while on the highway...it got COLD! Sitting at idle...not so much. The van only had a front AC unit, and didn't have the optional rear unit, but it was sufficient to cool the entire van. These systems were good, but I still liked the previous generation TXV systems used with the A6 compressor on older vehicles.
I had a 78 Malibu classic that I bought new while It was cold my brother-in-law 80 Pontiac LeMans was super duper cold I remember riding in the front seat ,my wife in the back seat. It was hot and humid outside . I couldn't wait to get out to warm up
Hell yeah. I got my first car in 1992 and it was a 1978 Monte Carlo Landau. Had the center console shift and the 305 V8. The car was in pretty mint condition when I got it, it was the cliche "old lady car bought brand new and garage kept and used only on the weekends to go shopping. It was 100% original with only about 30,000 miles. That AC would blow ice chunks! I also had a couple 1987 Trans Am GTA's and the same, super cold AC and I live in Miami where it is HOT and that AC would start blowing cold in 5 seconds.
This is off-topic of the generation AC systems this video is about. My grandpa‘s 2002 GMC Duramax, if you put a water bottle in the cup holder of the center consul and have the AC blow on it, it will freeze the top of the water bottle. This will happened anytime you’re driving for longer than 30 minutes with the AC on. If you let it that truck will freeze you out even on a hot 105° summer day. I don’t know what it is but that truck has fantastic AC.
I have a 2002 Suburban...has largely the same AC system, except it has a rear evaporator in it. You'd think a big truck like that would be hard to cool, but It was over 90 degrees here today, and I had to turn it OFF because even on the lowest setting, it was getting too cold inside!
When VW was designing the cost is no object Phaeton, they fitted it with an orifice tube system, not a TX valve system like most of their other models. Makes ya think!
I miss the a/c in my 2007 sierra classic, it would make you COLD during the hottest of phoenix summers
I have a few vehicles still on R12, mainly old Euro cars. My C4 Vette has it with the Denso comp.
Cost of 12 has dropped so much one can find it pretty reasonably priced now. Always cheap in bulk too.
Stick with the R-12, it might cost you an extra $100 or so dollars, but that's not much more than a tank of gas nowadays.
@@johneldorado I have about 70lbs of it, good till I die! Converting a 12 to 134 PROPERLY is not cheap, nor easy.
Also ceramic tint makes a huge difference. If you folks dislike it, 85% is available which is near invisible.
I love car AC systems almost as much as the engine itself!
My 87 Gand National had by far the coldest AC of any car I've owned. It was amazing
1 of the best is correct...The best was the CHRYSLER "AirTemp" of the 1960s trust me you could hang a Deer up on the coat-hook to cure in them. You had to drive around with them on Low or get frostbite in Tampa. They even switched their technology over to home window units and they were just as good. When the compressor would kick on those bad boys they'd shake and vibrate a brick home. Chrysler also made an outstanding Outboard Motor too. Good Video KUTGW
Hey man - this is a comment section on GM - keep your Chrysler comments to yourself - just kidding😀.
Chrysler Airtemp was an innovator in putting AC in cars back when AC was a new innovation.
Airtemp was huge - my grandfather had a Chrysler Airtemp furnace and A/C in his home. I think Chrysler sold Airtemp to Fedders. He also owned a Chrysler New Yorker that would freeze you out.
It is amazing how both GM and Chrysler built their own components back then and now you find Denso hvac stuff in newer offerings.
@@johnrose3169 "Hey Man"... I've owned FoMoCo's and I've owned MoPops [MoPars]. But the fastest car I ever had was my 1970 Model 396 Nova. That mother would pull the front wheels. CHRYSLER pioneered lots of things on cars. The HEMI. [Pratt & Whitney was really 1st] Power Steering, Power Brakes, Torque Converters. They were the 1st to go from Generators to Alternators. They drove a car with 2 drivers from NY to LA with no battery in it. They just never shut it off. And Ahh the Gas Turbine Car what a work of art that was. I LOVE my MoPars. That's why my 396 Nova half-tracked my best buddys 440 Cuda. With his wife in the car!!! hahaha LOL
And into the early seventies, the top line Chryslers could be had with REAR heat or REAR air conditioning to negate any weather from Death Valley to Prudhoe Bay...
They made the boats themselves too.
@@garyszewc3339 Mine has a tag on the transom that says ... *"Made for CHRYSLER by TaylorCraft."* The Trailer has a "CHRYSLER" moniker riveted to the side rail.
I remember my dad owning multiple GMs through my childhood. They were used and not in terrible shape. All of them had this system, and they all failed.
Yup… at the end of the day it’s still a GM
my old Chevy van that was 20+ years old still worked, but it would loose about a can of refrigerant every 2 years or so.
As bad as they were, they made the system used in the 1985 and 1986 Nissan Maxima seem good.
My 83 Silverado, after I converted to R134, still had the best A/C of any vehicles I’ve owned since.
The even earlier Fridgidaire compressors were even better than the pancake compressors in this video. They used R-12 also. Several vehicles I had from 1968 to about 1978 models would blow frost out of the ducts. We had a few that were not pumping R-12 as it got more expensive and then obsolete. We used propane. Worked awesome !
My 82 vet was converted to R134 and even with an upgrade to a parallel flow condenser, it's just barely adequate for down here in FL. I bet if it was still R12 that would be a different story.
I had a 78 Eldorado also converted to R-134 with a new condenser. Absolute garbage, like 65 degree air. Took it to all sorts of experts, they said thats as good as it gets with R-134. Knowing what i know now, either get the R-12 or look into some of the hydrocarbon drop ins like HotShot. Thanks again to the tree huggers.
Mine was greatly improved by inserting neoprene insulating foam along the left and right side to seal the gap between the radiator and condenser.
Also while replacing a leaky heater core, I discovered the evaporator was full of dust. It blows more air now the fins aren't blocked with decades of debris.
@@johneldoradomodern 134 systems have a larger condenser coil along with electric radiator fans. You could try upgrading to a larger radiator fan, this will help it cool down more.
@@tomtom154178 eldorado had an engine driven cooling fan. 134a condensers had smaller tubes and more of them but were the same size. If that Caddy has a VIR valve it has probably failed.
I am in Texas and can get down to 30F out of the vents on a 115F day from a a GM AC system without using R12 or Propane.
I have a 1993 trans sport van. The first year for a factory r134a system. It produces 32 degree air at the vent.
I once was told in a old school a/c class the system capacity for a 1970-80 era sedan was 3 tons and that it could cool a 1200-1500 square foot home.
the problem with recharging with R12 is the cost. if i had an older car that used R12 i would do a conversion. the coldest AC i think i had was a 91 cavalier, that thing would almost push icicles out of the vents LOL
I remember my 99 Yukon would blow cold for about 5 minutes then get hot. My rear air was still cool, being on the same compressor it took me a bit to get it. The heater control valve failed and it went to full hot coolant going to the heater coil and the front ac was routed through the heater so it works until the coolant warned up. Most ac on cars i have fixed were overcharged.
These were great. You could tell by the 50HP hit when the compressor kicked on. My only complaint is the dumb choice of a rubber ball in the service port instead of a proper valve core!
Yes. Rubber ball was a bad idea. Give me a Schrader valve. --Doozer
I sometimes would encounter 1970s and 1980s Benz diesels and Volvo bricks. I was suprised to see Harrison Thermal Systems AC parts under the hood.
CCOT did work, but I think about how expansion blocks were common in Chryslers, and common on some foreign cars. I don't know that the expansion block was what made the AC less effective in foreign cars, or if it was because the system may have been downsized to function. The AC was said to suck in the VW Vanagon and not in Ram Vans. Well, how much AC did that crappy WBX gasoline engine or tiny diesel take?
I always thought R12 cooled better, checking the boiling point of different freons, it seemed to be the lowest till todays freons. I went to great lengths to get licensed to buy R12 freon after it was banned because it worked so well in the old cars I still owned.
My '78 Fuuurd LTD 460 blew FOG on some days with Max A/C!
Old school R12 freon was the best!
Mopar had the best my 1972 Fury had that big V2 compressor. You could make a nice air compressor out of an old one. Also they could be repaired!
My R12 cars are running enviro safe or ES12. Definitely the better option.
When properly applied, R134a is just as effective as R12 and will still provide discharge air in the 38°-44° range. If your conversion isn't working right, it's probably because the desiccant in the accumulator is saturated or the metering device wasn't upgraded when the refrigerant was changed.
Not true R134a is a pile of crap because it requires much higher pressure than R12 refrigerant does and with the lower pressure of R12 could blow cold air on normal AC and only require max AC when it was over 100 degrees outside and when it was over a hundred degrees Fahrenheit you rarely had to run the fan at max speed when using Max AC about half speed would usually do and very rarely needed to be recharged with refrigerant like newer R134a do.
Yes, this is right. I’ve proven it numerous times on 80s GM Holden systems. R134a is fairly similar to R12 on the graphs but not quite as good.
(All Aussie GM Holden Commodores from 1982-mid 88 ran a TX, mid 88-97 ran a CCOT, but used R134a from’93).
However, changing to a suitable TX valve, fitting a new dryer, and boosting the cooling of the condensor with a bigger electric fan, and I blow fog out of my ‘87’s centre vents.
@@rustybeatty6567 I am an actual AC professional that understands enthalpy and psychometrics. You will not win this argument. Case in point, there's a very high probability that the refrigerator in your kitchen is charged with R134a. Does your freezer maintain -10° to keep your frozen food frozen?
@@nathanduke5323 then explain to me why modern vehicle AC system that runs on R134a power down everytime when hard acceleration of the vehicle is needed but when systems using R12 refrigerant almost never did.
@@rustybeatty6567 I can only speak to the thermodynamics of the situation which is that if there is the correct volume of refrigerant that is metered correctly causing the proper changes of state at the appropriate points in the coils, it will work as effectively as R12. But I imagine that the answer to your question has something to do with whether the compressor clutch is engaged or not and that's a part of the industry I am not involved with.
I had an old 68 fury that would freeze you completely out. It was an amazing how cold that car could get.
Oldsmobile LS Cutlass Supreme. The only car I ever have driven with better AC was a 1972 jaguar xj6 4.2 which I think also had the GM system.
While those compressors are large, were very inefficient, the same systems updated to a sanden style pump will also blow cubes.
I don't know how it compares, but my mom's '79 Fairmont ruined me for almost any other A/C system, especially modern ones. It would absolutely freeze you to death inside of a minute.
You never get all the mineral oil out unless you replace compressor and condenser. Just use ester oil for a 134a conversion. And use the same weight of R 134a as the R12 it called for. Don't use any refrigerant to flush the system out. As the R11 flush was cited as the cause of most conversion failures.
My 2008 tundra a/c is the same way. The fan doesn't produce a high cfm. But heater and a/c are awesome. And you don't have excessive wind noise of higher volume blowers.
One thing most people don't understand is. A/C is not producing cold air. Its removing heat! The most efficient any A/C, system whether its a freezer refrigerator or home central air. Is when a desired temp os achieved. To put the fan on its lowest setting. To allow the evaporator to be at its most efficient. So it can transfer the most heat to the refrigerant.
Actually high fan speeds makes the A/C run most efficiently as it means smaller temperature deltas but it also means less dehumidification.
Missed those awesome A-6 axial R 6 compressor R12 . awesome chill factor. Icicle hanging off your nose when set on high.😂😂😂😂😂
134 needs bigger condenser and more air flow. Old R12 had crank driven clutched fans and at idle or slow speed could not push enough air for 134. Install electric fans will help. At Highway speeds the two gases were the same in my car.
I wasn't around when these R12 systems were new but my 2005 Town Car AC is probably the best I've experienced so far. Wonder what truly ice cold AC would be like
That R12 stuff made it cold ; might of ate a hole in the ozone but it was cold in the car
It’s a big lie.
Those Harrison pancake compressors were absolute GARBAGE. I've replaced hundreds of them. We called them tuna cans. They all failed within a fairly short time, around where the case was welded together. They would leak around the welds. VERY poor design, as there really wasn't much of anything to weld to. The thin metal housing would flex, and the welds would crack.
I remember these systems having constant leaks from hoses and o rings.
They were awesome. A couple of my vehicles you could hang meat in their they were cold.
We had a 1982 S-10, a 1985 Camaro and a 1991 Pontiac Grand Am. Those things would freeze you to death, especially the smaller cabin of the S-10!
The same is said of the 1999-2007 GMT800, 2004 Tahoe still ice cold, no service
2001 Olds Aurora 4.0.....100* degree days......R-134a......within less than 5 minutes, COLD!!!!!
Great video, but I have to disagree. The CCOT system would cycle the compressor off too often when charged according to system specs. This was done primarily to save fuel. Unfortunately, wide variances in cooling, especially on a hot, humid day would occur. The way around it - was to slightly overcharge so the low side would not come down enough to activate the low pressure switch😊
Then the evaporator will ice up. -Doozer
@@kooldoozer I disagree - the point is - you're raising system pressure, both sides so the suction side doesn't pull down as low - triggering the compressor switch
@@ToddsHouseofSpeed-uq5sp Ok interesting. I am still learning. I currently use propane in my 95 Crown Vic for 6 years now, and it has been running really well. -Doozer
@@kooldoozer probably the best A/C system ever was the 1st gen GM systems with the A6 compressors utilizing the suction/ throttling valve. They were over-engineered, somewhat complex, but would spit icecubes out of the vents on a 100 degree day
What about r12 to HC conversion? You can keep the mineral oils then.
so, what made it one of the best? doesn't seem any different from a modern system, aside from using R-12.
Agreed!, r-12 was the BEST and it's actually been proven that its environmental damage was minimal.
R22 too. EPA is a joke. My uncle used to service their building in Detroit. The system has a leak. Eventually when they remodeled after 20+ years, they found where a drywall screw, had pierced a line in a wall. Until then, every month he would add over 250lbs of freon. At the same time, an A/C tech would get a $10,000 fine, for releasing less than 1 lb.
True story. I’ve been doing commercial/industrial HVAC for over 30 years. I used to take care of one of the original Westinghouse sites in Pittsburgh just before it closed down. There was an old timer that worked there and he told me they were building some type of vessel for the government. And to make sure all the welds were tight they had to pressurize this vessel with R-12 and go over every weld with an electronic leak detector to ensure the welds were good per government spec. Apparently this vessel was huge because it took several hundred lbs to pressurize it. When they asked the government what to do with all this R-12, they were told by the government to just open the valves and release it. And this was when they first banned releasing refrigerants into the air. The government said it was too costly and time consuming to recover all the refrigerant because they needed this vessel finished in a hurry. Rules for thee but not for me.
I still have a can of R12 with a Walmart sticker on it. 99 cents.
The GM refrigeration flow diagram mislabeled both the high pressure vapor and liquid as low pressure. All four refrigerant states were listed as low. No such thing as a refrigerant system without a high side lol
That's it!
I worked on many of these between 88-93. The system sucked.
1. The R4 compressor was junk compared to it's rivals. It would lock up, and take out other belt driven accessories, like the waterpump, power steering, etc. It would usually throw "shrapnel" into the system, requiring a new accumulator, orifice tube, and blowing out the lines to get the metal out.
2. If you overfilled the system it wouldn't cycle, and eventually would frost up the evaporator and stop air flow.
3. When low, they would cycle so much and chatter it would cause vibrations for some of the smaller engines.
4. The system could increase the idle speed, but didn't do anything to offset the power loss cycling. For example, driving the expressway the vehicle would speed up/slow down.
5. In 1991 GM brought back the txv valve for some vehicles to smooth out the vehicle. They changed the name, but it was the same thing as the earlier system from before late 70's.
Most compressors call for a full system flush when it dies. Others even require replacing the whole condenser.
My mom had a 1985 Nissan Maxima and the Hitachi compressor died more than once. Having to deal with Florida heat and no auto AC is why I learned it in 2006 during auto repair class. Every one of those cars had constly dying compressors. In 1994, we all learned what a timing belt was because it went boom.
The Maxima did not come with a parallel flow condenser that required replacement when the compressor dies. However, it needed replacement because the compressor shrapnel cut through it.
When I read about how summer also sucks in Japan, I wondered how Nissan could screw it up.
People at auto repair shops called it "black death."
I had to replace Sanden compressors on VWs several times. When flush fluid came out, it looked like mercury because of all the metallic trash.
@@skylinefever Interesting. I have high respect for Hitachi products. The compressors I replaced on domestic cars usually needed a clutch or some type of failure that didn't cause the shrapnel to get sent through the a/c system.
@@rainmant5724 I doubt the problem in the 1985 Nissan Maxima was caused by Hitachi. All those cars were flawed. It had an awful cooling system. They were FWD and should have been given a better electric fan. That would have been awful for the high side of the compressor.
The Nissan 300ZX had a similar Hitachi compressor. However, it also had a belt/clutch driven fan, and those cars were less prone to AC problems.
My mom had one and a nearby frenemy's mom had one. Some friends had a 1986 Maxima, same problem.
It amazed me that since the Maxima had such blazing underhood temperatures, the Hitachi sensors tended to hold up and not light the check engine light.
No. The system that cycles the compressor is a terrible design. It wears out the compressor clutch from all that on and off, and sooner than later you will have to replace the clutch, and usually the whole compressor. The much better system uses a TXV or thermostatic expansion valve. Used instead of the orifice, is a thermally controlled valve to control refrigerant flow. The compressor clutch stays engaged and the system flow (temperature) is regulated by the constantly and automatically adjusting TXV. This CCOT system was cheap and brought customers back for clutch replacement. It is not the best. It was the low end cheap system. ----Doozer
R12 works better, but is way more expensive these days. R134a works about the same on a retrofit if you change to a R134a orifice and cycling switch also.
Converting an existing R-12 system to R-134A reduces overall capacity by about 25%. R-134A requires a condenser with a larger surface area to reject the same amount of heat. On the low side of the system, the pressure is basically identical between the 2. Usually on commercial refrigeration the same TXV is used with either.
I have an unopened 12 oz can of r12 still from my grandpa
Is this used in a 1990 Cadillac brougham?
If you're in a humid part of the country and crank one of these systems they will blow clouds out of the vents.
Tiny ice cubes would spit out of them sometimes.
The error is that low pressure liquid and vapor on the right side of the key should be labeled HIGH pressure liquid and vapor.
If you put isobutane (r600a or r12a for sales purposes) in this system it works even better than r12.
Solid Black Line ,left of Orifice Tube should be labeled, "High Pressure Liquid"
Yep.
Would that be the same system used in my 1996 Daewoo Cielo? The only differences being that the low pressure switch is situated on the high pressure liquid line instead of the accumulator and 2 extra switches are present on the high pressure vapor side on the back of the compressor. One is wired in series with the low pressure switch for A/C request signal and the other goes to the ECM and switches on the cooling fans' high speed when pressure gets too high.
I suppose you could open a parts catalog and search for new orifice tubes. Also, you could search for not having:
TXV
Expansion Valve
Expansion Block
You mentioned one of the greatest car AC systems of the late 80's and onwards found in GM cars. That uses a Delphi V5 compressor or it could be marked as Daewoo but it's the same, it's simple easily servicable ancient technology and works on R134a.
It is even fitted on cars with 1.3 liter engines, when it kicks in it will use the whole engine just for spinning the compressor, but you will get so cold that you will have to turn it off after a while.
On the cars with electronic-automatic AC controls it's honestly everything you need in a car.
R12 was night and day better at cooling. I got a 66 Galaxy down to 34 outlet temp on a 90f day.
30 year old Lexus: “am I a joke to you?”
The R4 compressor was junk, i had a 77 Chevy caprice my uncle pulled the engine and put another engine in but didn't put the air back on i collected all the brackets to put the A6 compressor on and it worked great.
Daaayum! The Cut Dawg in the thumbnail is ice cold!🤗😌
R12 is the best! But Chrysler was far more efficient and better in my opinion with their scroll compressor and thermostatic expansion valve in the passenger cabin on the evaporator.
I miss the A/C in my Caprice Classic Brougham. Miss the whole car. I'm driving an 05 Honda Civic. It's too small, too noisy, the A/C sucks, it has no power, and I could keep going
R12 systems was the best.
The condenser is in the wrong line location.
I put propane in mine‼️ LMAO. Will freeze a drink sitting in front of it‼️ ya✔️☝️
Yeah its how it is. Best refridgerants are toxic. So as we progress we must raise pressures to keep effciently. In r12 systems where cold, the old cutlass' did freeze u out
i am a hardcore chevy guy, but every one of these ac systems i own have failed/leaked, and i hate to admit it but the best (*dependable) ac i have ever seen was on a 96 mustang, yeah , makes me sick.
It may have been the best system gm had, but not the best system. Chrysler s V twin compressor, and TX valve was a much better system.
Compressor to condenser is high pressure gas. It's not low pressure.
I AC deleted mine on my 80 cutlass...don't need it rolling down the window is my AC😂
S10 will freeze you. When there's a lot of humidity little ice chunks will shoot out the vent it's that cold.
Both my grandmothers Ford LTD Crown Victorias did the same thing and could run on normal AC for most of the summer time only needing MAX AC when temperatures outside were over a 100 degrees Fahrenheit at half fan speed.
I don't understand why these guys convert it to 134 you can still get our 12 it's 30 bucks a a pound and most units don't use more than 4 lb you'll never be the same if you convert it just telling you
I 100% agree.
The blower motor in today’s vehicles are loud and push way to much air and the cooling effect is not as pleasant as the old GM cars.
GM went to this because it was cheap, then Ford jumped on the cheap bandwagon, Chrysler never went to it and use a real expansion valve like a real AC system , semis use an expansion valves because all their systems are custom made and box trucks and Thermo kings all have real expansion valves
That, and most Japanese cars used expansion valves.
The air was cold but it took a third of the lame engines power to run the AC compressor!