914runner

When I did my engine swap I put my original R-12 AC compressor on and then looked into recharging the system with R-12 refrigerant, I was quoted $250! So for the whole summer now I have had no AC and am finally looking into my options.

What I would like to do is do a complete swap of all AC components (R-12 to R134A). I think it was in '92 or '93 that 2nd gen. runners came with the R134A refrigerant and AC components. So what I was thinking was to get all the R134A AC stuff from a R134A 2nd gen. runner and swap it all into my R-12 2nd gen. runner. Has anyone done this?

What I assume I will need is (R134A AC stuff):

Condensor
Compressor (have)
Hoses
Big black thing under dash
AC amplifier
Wiring

So if anyone knows anything about this chime in!
Thanks

HondaTec521

You dont need any of that stuff,WallyWorld(walmart)PepBoys sell kits to convert to 134a for about 35 bucks.You should put the system under a vacuum for a long time(3-5 hours to remove as much residual r12 as possible.Then recharge and go !

98 Joes

You don't neccessarily have to change all those components. I've converted 3 vehicles and never had a problem. If you already have a R-134a compressor, use it. Change your reciever/dryer (looks like a black can with 2 tubes going to it, located just behind the grill probably). Change any O-Rings where you have disassembled something. Use a R12 to R134a conversion kit and you'll be good to go. Take the truck to a certified AC shop and get the system evacuated properly. It won't cost much, around $25 usually. Now comes the bad part. After you change anything you want to change, you should take it back and have them put a vacumn on the system again to pull any moisture out of the system from it being open to the atmosphere. Most people don't do this and I've never really heard of problems form not doing it, but I wanted to mention that it is right way to do it. Also, remember to fill the system to 80% capacity with the R134a as compared to R12. If your truck requires 1.5 pounds of R12, fill it with 1.2 pounds of R134a. R134a is not as efficient as R12, but certainlly good enough. I'm getting a duct temperature on my 4Runner of about 35 degrees with a 90 degree outside air temp.

Gadget

Man, are they playing you for a sucker.

Forget the R-134 convertion, like you said, for it to work properly you need to change most of the damn system. R-134 is no where near as efficent as R-12 and there are some serious compatability issues with the system componants.

So, that leaves you with using R-12, still available, but is getting really expensive. The other problem with R-12 is the bootleg stuff that you don't really know what is in it, like flammable gasses such as butane.

Is there a better option?? You bet your ass there is. It is called R-406a. It is cheap, and it is a DIRECT drop in replacement for R-12 with no convertion of ANYTHING needed.

So, just get it completely evacuated and recharged with R-406a.

Another tip, ask the shop that is going to do the work if they use a refridgerent identifier? If they do not know right away what you are talking about get your truck away from them quick. If they do not properly ID the stuff the vehicles they work on and use the proper proceedures their equipment gets contaminated and in turn contaminates every vehicle they work on including YOURS!!!

Gadget

914runner

Where can you get this R-406A refrigerant?
Thanks

Gadget

My guess is any automotive A/C shop that has it's act together.

Gadget

98 Joes

The R406a is definitely more efficient than the R134a. I'm not saying that there is more than a remote chance of it happening, but R406a contains some flammable material, such as Isobutane and Methane and could pose a fire potential in a front end collision . And before anyone jumps up says what about gasoline. There is G-switch on vehicles that shuts down the fuel supply in a collision so that there is no fuel discharge under pressure. No such safety feature exists for the air-conditioning system. I'd rather trade a little efficiency for safety, even a remote amount. Here is a copy of the MSDS sheet showing the contents and hazards of R406a.

http://p2library.nfesc.navy.mil/msds/r406a.pdf

Just as a comparison, here is the MSDS sheet for R134a.

http://www.cooltop.net/pdfs/ct_msds.pdf

Interesting thing is both contain as a main incredient, ethane, with is non-flammable. R406a adds the isobutane to the mixture solely to be compataible with the old R12 oil.

ilion

Another important thing is the oil in the compressor. Make sure you change this as it can contain residual R-12.

Just something my gf's uncle/auto mechanic told me.

98 Joes

Absolutely true also. That's one reason for having the system vacumned by a certified shop.

For anyone interested, here is pretty decent article on A/C servicing and conversions.

http://www.delanet.com/~pparish/retrofit.htm
and the Toyota Page:
http://www.delanet.com/~pparish/toy-rp.htm
and one more for anyone who just loves this stuff.
http://www.delanet.com/~pparish/custinfo.htm

Flamedx4

GAdget, those are pretty harsh words regarding R134a conversions, considering that you are wrong. I helped one of the US automakers' OEMs and a major vehicle manufacturer pioneer the changover years ago and have personally monitored the results of thousands of conversions - they work perfectly 99% of the time. The vehicles that had problems (after weeding out improperly done conversions) all fell into ONE category - the factory equipment was crap to begin with. (Read: certain brands of known-to-be-poorly manufacturered cars and trucks of certain vintages. One of these is American by the way...)

Evacuation is to remove moisture. Any residual R12 (there won't be enough to think about,) and the residual oil doesn't hurt at all, it's important to remove the compressor and shake out as much old oil as possible though, and put in the correct new oil. If the original equipment hoses and fittings were of good quality, and the kit is of good quality and installed properly, the conversions should hold their charge for many years, and the components should last just as long as they originally would have with R12.

jns

There is also some freon called Redtek 12a which I put in my 91 4Runner.It's a direct replacement for R12.I could never find the 406a.The Redtek freon has larger molecules and won't leak out like 134a or so they claim.You only use about 35% of the capacity of the system and it's cheap.I 6oz can is equal to 18oz of R12.Do a search for Redtek 12a.

Flamedx4

The problems with compatibility with compressor life with 134a and the inevitable mixing of pag, ester, and mineral oils just didn't surface, the real problem is "leaking out." We originally thought the hoses would need replaced because the 134a would percolate right through the rubber. While this does happen it's not bad and isn't the problem - the problem is the crimped-on ends, and some compressors don't have very good shaft seals. Some hose ends are 'tighter' than others and the 134a is slippery stuff and gets out.

As far as conversion, the correct parts and then a proper vac down before refilling is key, and charging it with gauges rather than estimating the amount makes a huge difference in system performance.

Tacoma Dude

I'll have to look into mine. I'm still blowing out black snot from all the dust on the Big Bear trails

harpen123

how much does it take to fill the system from empty.

91TPU

haha good thing i can some cans of r12 sitting around, altho my A/C blows ice cold, not that i use it anyhow...only wish i would have taken the big tank of r12 from my pops before he gave it away, i didnt think i would have any use for it, but with going back to an older vehicle, it would be nice to have...

914runner

Holy old thread of mine batman!

I still have yet to do this swap, been through 2 summers without AC. So Im hoping I will actually get around to it by this summer.