Air Conditioning Conversion

[Greg Morgan]

Does anyone know what is involved in converting an air conditioning system from R-12 to R-135? I have an '85 GW and it's getting hot here in Texas, so I need to get the a.c. up and running.

[OBX-AUTOMOTIVE]

OH,NO!!!!!! TAKE YOUR DRYER,PUT IT IN THE OVEN,"THE SAME OVEN YOU USE FOR HOT COAT" THEN CAP EACH IN,WHILE IT IS STILL HOT! THERE IS A POST THAT I PLACED LAST WEEK OR SO. ON THE SAME THING...CHECK IT OUT!!!!!!!!!! GEMOBX/77/401***GOOD LUCK***

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[Brazzy]

Having done this mod last year Yes I can give you advice. If you can stay with R12 it will be easier http://www.ifsja.org/ubb/biggrin.gif Really though, I did mine and the expansion valve was bad (unbeknownst to me)Well this caused all kinds of exploding hoses and seals. After replaceing the compressor,both gas hoses,drier, condensor,and finally expansion valve, that sucker works real well. The tech section has a good article and emphasises pulling a vacume prior to refilling. I didn't and it has worked very well, works great even today.

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Brazzy
Formerly abused 87 G.W. 175k
TOW,PKG,727,229,360
2.5" Rancho softride AAL
The Chariot

[Rick]

hey greg, some places sell a replacement for the R12 that is enviroment safe. the bad part is i cant remember the name of it. http://www.ifsja.org/ubb/frown.gif ill get back to you on the name.

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87 Grand wagoneer/360/D44's/TF727/NP229/for now.(full blown project)
85 Grand Wagoneer LTD (parts beast)
NP229/TF727/D44/AMC20/Warn Hubs/
15x8 Black RockCrawlers/stock tires :( for now ;)
FSJ's FOREVER BABY
my site www.geocities.com/thewagoneerman/ (http://www.geocities.com/thewagoneerman/)
1978 Kawasaki KZ650(project #2)
90 pontiac sunbird

[Usmar]

It could be Hotshot your thinking of

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Sergio & Ulrike
'75 Jeep Wagoneer "Extreme"
AMC 401/Edelbrock Power Pkg/K&N AF/TH400/3.54's/5" lift/35X12.5X15

[Michael F]

Wooo no vacuum! If you purged the air out of the system with the 134a, you may be ok, but if you did not http://www.ifsja.org/ubb/eek.gif the older systems do not have high pressure switches!! Air can not be condensed inside the a/c system and will force the system to run super high pressures and posibly explode or at least damage the system.

The R12 replacements that can be purchased without a licence besides R134a are hydrocarbon based, aka propane and or butane.

To install one of these no matter what they may tell you is to litterly play with fire. I have not looked into all of them but a lot of them use better than 50% concentrations of the hydrocarbon of choice. There are to many ignition sources inside a FSJ to have propane or butane leaking into the pasenger compartment.

A good alternative is Hotshot. A dumb name but it works real well and has a A1 safety and flamibility ratting even though it containes 1.5% isobutane. You can not get it though without a licence.

To get a licence go to www.macsw.org (http://www.macsw.org)

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56,000 orig. miles (not the engine I6 to V8 conv.)
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4" BDS lift/TrailMaster SSV shocks
79 Cherokee Chief WT (snow plow)
360/400/QTw/LR/3.54/31x10.5

[desert_freak]

I have researched conversions in the past and while some people have success converting to R-134a (provided you switch all the required parts, including your hoses to "barrier hoses'), I am planning on giving R-406a at try for my next retrofit.

It is a R-12 replacement that is designed to operate at the same pressures as R-12, thus no valve or switch replacements. Unlike R-134a conversions that often push warmer air than R-12 the R-406a produces air 3-12 degrees cooler than R-12.

It does have it's own limitations in that the system is not supposed to be topped off, but instead evacuated and recharged, but the refrigerant is much cheaper than R-12.

If anyone is interested they have a website www.autofrost.com (http://www.autofrost.com) If you search on R-406a you will also find info on the product.

Just thought some of you might be interested in an alternative.

Now if my J10 only had air!

Patrick


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The fun has just begun! Resurection began on 4/8/01.

[millerlo]

Your right DF. 406a has a boiling point that is close to R-12, and was "blended" to simulate the properties of R-12. Many commercial refrigeration units like walk-in coolers and freezers use it as a direct replacement for R-12.
I converted my '89 GW two years ago, purchasing a new R-12 compressor and the retrofit oil change for it. When replacing the oil, there is a "bolt" with a "O" ring on the side of the unit that you remove to drain the oil. Put it in a graduated measuring device that will show onces. Read the amount that is taken out and then measure the new oil to the same amount adding all but 2 onces back into the compressor. Place 1 oz. into the the condensing coil and the remaining 1 oz. in the suction line letting it run back into the evaporator. All of this has to be done after you have flushed the system and purged it, I use a anahydrous or dry nitrogen gas plus a solvent or flush. (Air Pro Part#09530 Clear-Flush)("For flushing particulate matter and lubricant from: A/C and refrigeration sytem evaporators,condensers and lines") This is also compatible with PAG, Ester and mineral oil lubricants, CFC,HFC and HCFC refrigerants. This forces the old oil and contaminants out.
Inspect your hoses and replace if they show signs of breakdown. Replace all "O" rings and seals as well as the filter drier. Vacuum the system 29-30mm Hg and close your hose set valves. If you have a system that leaks, the reading will slowly creep up, in which case the job becomes harder.

If you want to charge your unit with R-134a go for it but it will not be as cold as R-406a. I use a 2 stage vacuum pump which will do a better job. Remember that you must remove all moisture from the system. When overheated most oils will acidify if any moisture is present.

If you are going put put some expense into the system and you want it done right and you don't know if you can do all of these necessary things then by all means let a professional do it.
Mike

[Brazzy]

Hey Micheal Thanks for the warning. But I think youre wrong on a few facts. Air is compressable anywhere (Navy diver 15 years) The vacume is to insure removal of moisture. The a/c system does have a pressure cutout switch. If 134a is flamable I kiss your arse.

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Brazzy
Formerly abused 87 G.W. 175k
TOW,PKG,727,229,360
2.5" Rancho softride AAL
The Chariot

[Michael F]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Michael F:
Air can not be condensed inside the a/c system and will force the system to run super high pressures and posibly explode or at least damage the system.

The R12 replacements that can be purchased without a licence besides R134a are hydrocarbon based, aka propane and or butane.


<HR></BLOCKQUOTE>

Brazzy, Notice I said air can not be condensed inside the A/C system just compressed. The refrigerant is condensed in the condenser and sense the air can not be condensed at the relatively low
pressures the A/C compressor can produce, the compressor can still produce high enough pressures to blow the system apart or trip a high pressure relief (if it exists) if enough air is pressent. My 79-81 FSJ A/C systems do not have a high pressure switch, but the newer systems do.

And yes removal of moisture from the system is also extremely important. http://www.ifsja.org/ubb/biggrin.gif

Also notice I said besides 134a .

Miss a few days of posts and look what happens! http://www.ifsja.org/ubb/biggrin.gif

[okidoc]

Ummm O.k. I wasn't going to do this but...

I was looking into doing the conversion. I sourced all the parts hoses, accum. pressure valve etc... close to $300.00 and 1 day's work. So then I thought I'll just add the 135 and see what happens. Figuring I'm going to have to replace/pull it anyway.

I get about 64 degrees from the vents on hot days. I did the conversion about 4 months ago, no problems. Ran the Jeep to Corona(100+ miles) and back no problems. I did evacuate the system first though, for about 45 mins and added a can of 135 oil, as my system got vented by my ex-mechanic when the motor was redone and I was pretty sure all or most of the oil was out.

Not a recommendation though. Maybe I just got lucky

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