XtraSlow_XtraCab

Ok, so I've searched this topic all over this site and could not find the EXACT answer I was looking for.


My AC system has been dry for who knows how long. Its the old R12 system. I'd like to just convert to 134 and was wondering, who else has done this?

My friend, Drew, has a 1982 truck and all he did to convert was change some sort of fitting on the compressor (the belt-driven thingy is the compressor right?) and fill it with 134. Anyway, the 82 blows nice, cold air!

Is this all I would have to do... change the fitting so a 134 bottle fits? I'm thinking I'll change the seals on the lines so as not to let possible R12 residue mix with the 134.

Does anyoen believe that this may be all I need to do? I know there are several opinions on the "right way". I'm just looking for the cheapest.

Thanks dudes.

Richredneck989

I have been wondering the same thing and have yet to get the 'correct' answer anywhere. I was going to do a seal replacement also. I will continue to look for mire info and will post if I find it. Might just go dig up some R12,

OK here is a link to more info on AC's. also do a search here for ac, 134

https://www.yotatech.com/forums/f116...12-r134-88019/

AustinTaco

I just did my 89 4runner and I am using it as the test mule for my 84. You will get conflicting advice from "you have to change everything" to "you just change the fittings and go", but I think the truth will depend on the current shape of your system.
When I had my system done, they switched out the drier and Orings, but left the stock fittings. Apparently, they have problems with the 134 fittings that retrofit the r12 fittings leaking so they leave the r12 fittings on and adapt the filler bottles.
At first, my A/C worked great, but then it crapped out completely after about 2 weeks, and I ended up having to buy a new compressor.
The new compressor is made for 134, so I shouldn't have any problems, but I will keep the board posted if I do.
Go on ebay or check craigslist and you can find r12. Check your system for leaks, and then just refill. It will work better and will be less expensive. I have $500 into the A/C at this point....

frodin1

You can get conversion kits at Walmart? For like $30.00. I've heard people using them and never having a problem, but on the other hand people have leaking issues. I'd try that first, make sure you seal everything good. If it doesn't work your only out $30. I've never heard of anyone not being able to make it work though.

XtraSlow_XtraCab

Hmmm... I might go buy a junkyard drier, new o rings, and try the old system with 134 in it. But please, keep me posted with your progress too!

ssupercoolss

do yourself a favor and just buy a new drier. i wouldnt waste your time because they are fairly cheap and its a crap shoot if one from a junk yard is any good. here's the skinny on conversions. the 100% percent correct way to do this is to actually disasemble the whole a/c system and flush everything (condensor, evap, and hoses) with flush solvent. replace the drier, orfice tube, or expansion valve, and every o ring. need to drain the oil out of the compressor too. then add the proper amount of ester oil, normally about 4 oz. 2 in the drier, 2 in the compressor. vacuum the system after reassembly, check for leaks, then charge the system with 134. that is the proper procedure for converting from r 12 to r 134a. sounds like a great big pain in the a==, doesnt it? it is, trust me i've done like 30 of them.

but.....i have done it the other way too, like with that kit i've seen, which i think is nothing more than the two shrader valves, and a can that looks like a can of fix a flat with a hose. sometimes i've seen it with a gauge on it too to tell you if you are low or not. which is kind of funny because thats the most in accurate way to tell if you are low or not.

you can do it that way. i am not going to say this is the wrong way to do it or the right way. i have done it this way with more success than failure. older compressors tend to fail due to the high head pressures with r-134. and supposedly r-134 is not compatible with mineral oil used in an r-12 system. but....if your system has been open or completly emptied of freon, you need to have a vaccuum placed on the system, before you put freon in it. dont bother putting freon in it if you cant put it under vacuum. thats pretty clear, right? i cant tell you how many people have come to me or asked me why their a/c isnt working right, when they had an open system and just added freon without putting a vacuum on it. it will cool a little, but no where near what it should do. i've also seen it create some crazy high pressures, which is probably why a lot of compressors fail when people do this. if you do charge this system on your own, be careful how much you add. adding too much is worse than being too low. i cant off hand remeber the figure, but it think a converted system is supposed to hold 80% of what your r-12 was.

sorry this is long, and i hope i answered some questions, but filling your a/c system is not as easy as topping off your radiator.

hosh

I used the kit with the gage once on an s-10 blazer. It had leaked dry. So i also used a can of the ac stop leak.

I was lucky i guess, cause it worked for me. I don't think it was quite as cold as an r-12 system, but it was cold enough.

nieuwendyk-25

You must flush the system before replacing the Refrigerant. The compressor oils for R-12 are not compatible with R-134a.

Do not buy a junkyard drier, the dessicant will not be dry!

XtraSlow_XtraCab

Okie dokie then. Thanks for all the input on this, especially ssupercoolss! When I'm not in the hole anymore, I'll consider investing in a new drier. My only worry is spending THAT MUCH, only to have the compressor go tits up on me. IF that becomes the case, I'm just gonna give up and pull the belt off (maybe trade comfort for some actual horsepower).

But, its still worth trying the at-home conversion kits.

Robrt32

Most "professionals" say what i done wont work but it did.. My truck had a bad compressor. I bought 1 off a junk motor for 10 bucks. I bought the 134 adapters and a new drier .. I put the drier on charged it and the rest is cold air in my face..might work for you might not , but thats ALL i done.. never cleaned a line or nothing.. This was 3 years ago!! The cheap fitting on the low side started leaking on me this year and i bought 1 from John Deere and its much more beefy and i was good to go

deserttoy84

I just changed the fitting on this one honda and then filled it up. Its still working

XtraSlow_XtraCab

Actually I was going more for the five finger discount Sorry... asking for admission to go in a yard that "might" have what you're looking for? Where it "might" work? I need to look out for number one.

Anyway, pay day is tomorrow!!! A/C here you come!

bigtrucknwheels

i have a few friends who do HVAC. I think ill get them to do my A/C in my corolla. Shouldnt cost me more than the refrigerant. Hopefully.

Id do it myself, but i dont have a vacuum pump and dont know where to get ahold of one...

locked stock 84

http://autoacrepairs.com/134aConversion.htm
try this

AustinTaco

A/C is out again. I really like my mechanic, but they have been having a hard time with this A/C conversion. All of the new 134 refrigerant leaked out via the expansion valve...again. I think my whole system should have been cleaned to begin with, but they gambled and now we are paying the price in time and labor...

XtraSlow_XtraCab

I'll admit... that link was helpful and confusing at the same time.

Where can I find the expansion valve on my system and is there a way to check for leaks without wasting refrigerant?

-Dan

rev8n

To be honest most mechanics are not great at repairing ac systems, also to use a HVAC tech on a car system for conversion is a bit of a pickle. There are a few keys to understanding how everything works.
The compressor puts the refrigerant under pressure and sends it to the condensing coils. In your truck, these coils are in front of the radiator (I believe). Compressing a gas makes it quite hot. In the condenser, this added heat and the heat the refrigerant picked up in the evaporator is expelled to the air flowing across it from outside the car. When the refrigerant is cooled to its saturation temperature, it will change phase from a gas back into a liquid (this gives off a bundle of heat known as the "latent heat of vaporization"). The liquid then passes through the expansion valve to the evaporator, the coils inside of your car, where it loses pressure that was added to it in the compressor. This causes some of the liquid to change to a low-pressure gas as it cools the remaining liquid. This two-phase mixture enters the evaporator, and the liquid portion of the refrigerant absorbs the heat from the air across the coil and evaporates. Your car's blower circulates air across the cold evaporator and into the interior. The refrigerant goes back through the cycle again and again.

Now when you want to convert your system to r134a or what ever, water for all i care in theory it will still go through the same process, efficiency it the key. That is why people generally say that r12 is a better coolant than r13a. The issues arise when you have component, like the dryer that is not able to handle the difference of the in refrigerant. Most American made r12 systems can't take 134a with out a problem. The most common issue is the compressor. Toyota's uses a really efficient design that will generally not die with the new gas. I say generally because overcharging the system will kill your compressor.

If your ac once blew cold air and now over the last five years has slowly stopped my first be is a leak, and may times you will still have a bit of r12 still in their and let a tiny bit out you will know that you system still is holding psi. On the other hand if one day it just stopped you may have bigger issues and need to replace a lot of the components.

You will have a low pressure side and a high pressure side, and each have a pressure switch. These switches will cause the compressor to kick on and then off (if this is rapped, or it runs for a bit and stops that is usually a sign of too much gas or too little).

There is a third component to converting your system is the oil. The oil travels in the whole system and will keep everything tight and running smooth. Some oil are not compatible with others, where as others can be used with any system. You will want to find out what oil the system uses. I have seen years that have PAG oil and others that have POE (ester). You will want to find out what type of oil you have and if it is compatible with they Wal-Mart kit you will be using. Also if you just happen to have access to some type of vacuum system you can use it and suck out all the water and other crap the is in the system.

My suggestion is just try it and see what happens. Worst case scenario is that you convert it and it woks for 2 weeks you get use to it and then you hear a big bang and your dryer has a gaping hole in the side. Now you want to fix it cuz you have had the joy of ac and it will cost you a bit more.


It?s not hard to learn. Good luck.

XtraSlow_XtraCab

Ok, so I did the WalMart retro fit kit. Before installing it, all I did was hook up a vacuum for about an hour/hour & a half. I began to fill tie AC system and it was actually blowing out cold air!

My only concern is two things. First, the guage read that the system was filled to an acceptable level after only 1.5 cans of refrigereant when one should take 2.5 cans minimum. That's kinda freakin me out here.

Also the air doesn't blow as cold as it did 2 days ago. I know people say on here that 134 doesn't work well. Well, if was doing great the first day I ran it! But now, its only a little cold compared to the air blown just with the fan.

The drier has some sort of view window at the top and it looks like stuff is happening in there. I replaced 2 o-rings on the low-pressure line but that is it.

Can anyone shed some light on why my air is not as cold or why the pressure guage says its ok when I know there's not enough?

AustinTaco

I should get my 89 back tomorrow. The problem was a line that runs under the battery was corroded after years of being under a battery(this is what I was told, and it makes sense) so the new stuff leaked out via this line. I hope this fixes the A/C so my gf can start driving this truck again and give me back my Tacoma!