[black66]

What does it take to convert my 90 toyota truck to the new R134 AC system?

[302 Z28]

You will get varying instructions on this.
When I converted my 90 Chevy, I needed a new compressor anyway, so it was replaced. The system must be entirely free of any trace of the oil from the R12. The R12 oil and the R134 oil are not compatable, they will not mix and the R12 oil will remain out of supension. Your O rings may or may not be compatable with R134, you will have to research that. I managed to get away with using my original R12 orifice, and it works great. You may have to change yours out. Some people advocate replacing the compressor, as you can never get all the R12 oil out of it. The system must be opened up entirely and flushed with a AC solvent to remove the traces of R12 oil.

There us a wealth of information on this subject on the net. One site is http://www.aircondition.com/ just do a search for "R134 conversion".

Vince

[TooMany2count]

all I did was vacuum down my system, added the ESTER OIL & 134r and away i went, NEVER had a problem w/it.

you can ask this same question to 10 different people & you most likely will get 10 different answers. when they first stated the change over they wanted you to change all the oil, wash the system out, replace any orifice's, change the driers and a bunch of othe stuff too. now they basicly tell you to replace any bad stuff if ya got any & then vacuum it down add the ESTER oil & shoot the freon back in it. BUT remember that on some systems you will use about 1/3 less then w/R12, BUT in my burb I had to put almost the same amounts to get it to cool correctly...joe

http://www.nichols.nu/tip651.htm
http://www.miata.net/garage/r134.html

[black66]

Thanks guys..... I bought this truck for a work truck and the AC compressor was not hooked up. So I put a belt on it and jumped to start the compressor. The system had 0 pressure in it. So I went ahead and put 134 in it. The 134 hooked right up with zero problems.....

Everything was fine until I put the second can in. Then one of my fittings was leaking. Now on the fittings, do they have rubber in between for the seal? Because I was just going to replace all the seals that I could get to and test it again.

No leaks at the AC pump. And I cold only find one leak? So do the new seals need to be for 134? And our the seals a dealer thing. Or a Local part shop? Thanks for all the help.....

Dave....

[TooMany2count]

remember to use only about 85% of the amount that it needed for R12. as for the seals it just depends, on one car i did, nothing was changed, but on my burb, i did change all the seals, but then i was replacing a lot of parts too because my compressor went out. you should be able to get the 134 seals at any GOOD auto parts house, but since you have to replace the seals be sure to pump the system down also & do it as soon as you replace the seals cause if moisure gets into the system you'll have to replace the dryer also...good luck...joe

[60convert]

I usually suck thye system down make sure it holds then put in the compatible oil and pump it full again. at home my vaucuum pump is an old freezer pump out of a freezer i was getting rid of i use that and a set of gages and do it all from there.

[FASTCHEVY]

Freeze 12 cools better than 134a and is as cheap as 134a, and it works with old R12 and R12 systems.

[55mole]

#1 You should have pumped the system down to a negative pressure & let it stand to see if it holds . You also needed to do this to remove any moisture that could have accumulated in the refrigeration lines . If the system has been exposed to atmospheric conditions especially since you had "0" pressure , you probably have moisture in the system. This is not good for the compressor .
#2 134A conversion kits contain the estor oil , which gets added first . If you have not added the oil to your compressor , it is going to fail .
Wal-Mart sells this complete kit for almost half the price of an auto parts store.
#3 Just get replacement seals . But after you are done , pump down the system w/vacuum 1st . Make sure it holds . Leave it @ a negative pressure
than add the oil , then the freon . Do not let air into the system either , purge line prior to adding oil or freon .

[trees]

I have successfully converted a couple of systems. First, I bought a kit for each one. In the kit was the instructions and every thing I needed except for tools. Each kit included a new drier, an orifice, the correct valve to replace the Schroeder valve, the correct amount and type of oil and of course, 134a. After you break into the lines to replace the drier and orifice, you need to evacuate the system, just like any other refrigerant system. Also, it is a good ideal to take the lines loose from the compressor and spin it to puke out most of the old oil. Put a big rag over it cause you could spew oil every where you did not want it. R134a does cool to the same temp as R 12, it just takes longer to get there. One biggie is 134a is quantity sensitive. Over or under fill and it will not cool for squat.

Good luck.

Trees

[FASTCHEVY]

Originally posted by trees
I have successfully converted a couple of systems. First, I bought a kit for each one. In the kit was the instructions and every thing I needed except for tools. Each kit included a new drier, an orifice, the correct valve to replace the Schroeder valve, the correct amount and type of oil and of course, 134a. After you break into the lines to replace the drier and orifice, you need to evacuate the system, just like any other refrigerant system. Also, it is a good ideal to take the lines loose from the compressor and spin it to puke out most of the old oil. Put a big rag over it cause you could spew oil every where you did not want it. R134a does cool to the same temp as R 12, it just takes longer to get there. One biggie is 134a is quantity sensitive. Over or under fill and it will not cool for squat.

Good luck.

Trees

That's why 134a will be obsolete to the newer Freeze12. it does everything R12 did, and doesn't pollute the air.

[trees]

Fast, how about some more info on Freeze 12. The local parts store tell me it was taken off the market because it was poluting similar to R 12. Who makes it and who distributes it? Is it safe to mix with either R12 or 134a? What kind of fitting is required to charge the system or can you use either the R 12 or !34a fittings?

Thanks,

Trees

[FASTCHEVY]

Originally posted by trees
Fast, how about some more info on Freeze 12. The local parts store tell me it was taken off the market because it was poluting similar to R 12. Who makes it and who distributes it? Is it safe to mix with either R12 or 134a? What kind of fitting is required to charge the system or can you use either the R 12 or !34a fittings?

Thanks,

Trees

I was told that it only worked with R12 and R12 fittings.
As far as I know, I can still get it. I will get some onfo on it tomorrow.