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Discussion Starter #1
Of course there will be a lot of questions, but let me just say that I'm definitely not the pioneer of R152a conversions in vehicles. R152a has VERY similar properties to r12, and as many of us all know, R134a conversions don't really work as well as most of us wish. So if only there was some sort of refrigerant we could use in our old R12 systems that would work as well as R12 did.



Yes, good ol' electronics dusters. They contain r152a. You're welcome, everyone. I just used R152a today in my 91, and it's working great!

Here's a quick run-down of what to do:

Gather your equipment. You'll need everything pictured. Manifold gauges are pretty much a must. I used R-134 gauges because let's face it, when are you ever going to run into another time when R12 manifold gauges are useful? Get a NEW receiver/dryer, a new orifice tube, an R12 to R134a fitting conversion kit, a multi-pack of HNBR o-rings, 8oz of Ester oil, lots of non-chlorinated brake cleaner, a side can tap, and last but not least, rent or buy a vacuum pump. You'll need a source of compressed air for this job.



Let's start.

Remove all the lines. I started by removing the battery, it makes things easier. I've never seen such an dismal-looking battery tray. I'll fix that later :) Take the lines loose at the bottom of the condenser on the passenger's side.



I also removed the compressor to get all the old oil out. When I got the truck, the seller told me he replaced the compressor with a salvage yard unit, but he never charged it. So thankfully, the compressor never ran. Good, because almost every time you have to replace a compressor, you run into what's known as the BLACK DEATH!



Take the line off:



And remove the old receiver/dryer, and the bottom line off the evaporator.



New dryer, bottom line from evaporator:



Now, see the vertical tube sticking out the bottom of the evaporator core? Pull the old orifice tube out (straight up) with a pair of needle nose pliers. This, my friends, is the black death:







The compressor shits this stuff everywhere through the WHOLE system when it goes south. No big deal, a new orifice tube is $1.99, and a new drier is less than $30.

Now, here's why you bought several cans of brake parts cleaner. You're going to have to flush, SEVERAL times, everything. And I mean flush it all. Fill the evaporator, condenser, and all the lines full of brake cleaner, and blow it all out with compressed air. Hopefully, it entrains all the black death and oil out of your system. Do this numerous times.



Once you get every bit of anything in the system out, and it's completely dry and free of any oil or debris, turn the compressor over and spin it several times to get all the old oil out. Spin it backwards and forwards to get everything out. I like to add some oil to the compressor, spin it a few times, then drain it out the same way to sort of flush it out. Don't use brake cleaner on it.

Now, add your required amount of oil to the compressor. Mine was 8oz, others will be different depending on what type of compressor you have.

Install the compressor. Remember the orifice tube? I highlighted the direction it's supposed to go.



Notice, I have clean hands in this picture. Cleanliness is a must for AC systems. Install the orifice tube in the direction shown.



Reconnect all the lines with new HNBR O-rings, and make sure you lubricate them with oil. Reinstall everything, connect it all up!

Remember the vacuum pump? This is important. Vacuuming the system out removes any air bound up in the system. Regular air in refrigerant systems is bad because it's a non-condensable gas. It also boils off any moisture left over. Hook up the vacuum and suck it down to 30"Hg, and let it sit for about 10 minutes. If the vacuum held, continue on. If not, you've got a leak somewhere, and you need to fix it.

Hook up your manifold gauges and shut both valves. Attach the side can tap to the yellow hose. Tap the first can. This is where you BLEED THE HOSE! Once again, non-condensable gasses are trapped in that line, so get it out. You need to loosen the yellow line at the manifold gauges a little until just a tiny bit of refrigerant leaks out. It'll get cold, be careful.

Charge 2 cans, assuming you're using 12oz cans. The first one should go in with the engine off. The vacuum you pulled will draw the refrigerant in pretty easily. The second can will go in with the engine on, AC on (max AC) and the fan on low.

The reason I say 2 cans is simple. The molecular weight of R12 is 120. R152a is 68. A quick calculation, and 2.5lbs turns out to be 22.4oz. So if you use 2 12oz cans, that's 24 oz. Some will get bled out, some will not go in because the can tap is not exactly perfect science. Trust me, you'll get very close.


Looking back, I spent right at $100 for the whole thing. I already had the manifold gauges, but for an extra $50 at harbor freight, you can have your very own set. You'll pay an astronomical amount more than that to have your AC fixed at any garage, I don't care WHERE you go, it'll cost way more. In south Georgia, $150 is worth it for AC, especially if you get stuck in traffic.

I may be forgetting something, so don't think this is the absolute 100% service manual for air conditioning.
 

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Discussion Starter #6
This forum really needs a How-to or DIY section. I like making threads like this each time I do stuff to my own vehicles. It's good documentation for my own work, and potentially helps others at the same time. I was on a Tiburon forum years ago when I owned one, and there was a single sticky thread in their DIY section for requests. Other forum members would graciously post up a DIY for that request if they 1) had the proper technical knowledge , and 2) were getting ready to do that maintenance/modification/repair to their own vehicle. Pretty neat system that worked well.

I hope this spreads :)
 

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Discussion Starter #7
Cool right up on R152A, Never really heard of it before.
Does it really seem better then R134A? After reading your wright up I found this SAE Paper on R152a
It seems like a viable alternative to R134A,

Great question. Yes, it does seem better than R134a. I've been in numerous vehicles that have been converted to 134a from R12, and it just seems like they never really work the same. I need to look for it, but I found a study that proved that using 152a used approximately 10% less fuel to do the same job that R134a tries to do.

Turns out, though, that since R152a is flammable, there are tree-hugging pussies that are concerned for the use. The test involves spraying the substance at some set pressure over a lit candle flame. If the stream catches fire, it's deemed flammable. If the fire travels up the stream, or if when the ignition source (lit candle) is removed and the fire stays, then it's deemed extremely flammable.

Funny, though. There are apparently global-warming factors on several substances. R134a has a global warming potential of somewhere around 1300. R152a is around 140.

Hippie tree huggers around the world are getting pissed, and want to completely phase out R134a. The Germans have resorted to using CO2. CO2! Are you kidding!??! Do you know how hard it is to seal a system ,especially with a compressor that requires a seal around a rotating shaft, from CO2? You know those fancy little leak sniffers that automotive techs use? Kiss those goodbye. Everything generates CO2, so if you got some sort of CO2 sniffing device, it'd shit its pants every time you turned it on!

Some say the next step in automotive refrigerants is some crazy substance known as R1234yf. History's going to repeat itself, and R134 is going to be known as "the good stuff" just like R12 is now. Liquid GOLD!

Will R152a kill everyone? Is it going to deplete the ozone layer and destroy the future for your children's children? Well, potentially. But it's a hell of a lot better and far less baby seal-clubbing than R134. For something that the EPA says is OK for you to spray on your keyboards to remove dust, and just completely discharge into the environment, I can't see why using it in an automotive AC system is bad. Especially when it cools so well!
 

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R1234yf is suppose to be damn near close to R12 in cooling factor, (its also in price factor) Mercedes Benz is already putting it into 1500 of their 2013 SL550 and only 1500 because thats all they could get because its not readily available, that should tell you how much it costs
 

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Discussion Starter #9
I can only imagine how much it's going to cost. That figures though. Leave it to hippies to ruin it for everyone.


Stick it to the hippie fags. Convert your refrigerant to use keyboard dusters! :)
 

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how is this working out after a month?

my system needs a recharge of r12, but i am considering just overhauling the whole system, which is how i found this thread.

i'm guessing you are using the r4 compressor?
 

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bump!
 

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I seriously thought R1234yf was just a sarcastic joke but googled it and can't believe its really called that with the sequence of 1234 in the name haha. Anyways, from what I've read so far rumors are thinking it will be around 40 to 60 dollars a pound for the new stuff. Much more than R134a.

Heck its to the point if you run an R12 system you might as well get a tech to get you some R12 and charge your system for ya if you go the R1234yf route. Ridiculous.

I may just hit up my friend who is an HVAC Tech and see what he'd charge to flush the A/C and refill it with R12.
 

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would be nice to hear back from the op about how this system is working so far.
 

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Mine is 134 converted and it throws ice cubes out of the vents.. cools just fine. far as the OP having black death on the orifice valve... That isn't even close to black death.
This is black death.
his tube just showed old age.
 

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Mine is 134 converted and it throws ice cubes out of the vents.. cools just fine. far as the OP having black death on the orifice valve... That isn't even close to black death.
This is black death.
DAMN!!!!

got my system evacuated and charged this afternoon using the r152a.

it's blowing about 48-50 degrees at the vent at idle and max a/c on low fan with ambient outside temp of 101 and 4% humidity.

for the time being to test the r152a, i am using a new stock orifice replacement instead of the new variable.
 

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i am not sure if i had bogus readings or what, but while driving, i am seeing 38-43 degrees at the vent with outside temps of about 95-100.
 

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it will get colder when you are moving due to increased airflow across the condenser. if your fan clutch is weak, it could exagerate the problem at idle even more
 

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the fan clutch is new.

based on my experience with other stock vehicles, at idle the air does not get as cold obviously.

i am just trying to get enough info to decide if i want to use a variable orifice valve.
 

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R1234yf is suppose to be damn near close to R12 in cooling factor
Dont know where you read this but that is completely wrong. In fact R1234 needs a redundant cooling system (i.e. a second condensor insided the evaporator box) just to have the same thermal transfer capabilities as R134. We are all going to be taking it in the rear as far as refrigerant goes in the next five to ten years because of the tree huggers.
 

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Dont know where you read this but that is completely wrong. In fact R1234 needs a redundant cooling system (i.e. a second condensor insided the evaporator box) just to have the same thermal transfer capabilities as R134. We are all going to be taking it in the rear as far as refrigerant goes in the next five to ten years because of the tree huggers.
i don't know about you, but i think i'll be stocking up on ultra duster while it's less than 5 bucks a can.
 
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