A/C Conversion Problems
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A/C Conversion Problems
I have a 1983 F-250 XLT with factory air. The truck has had the A/C unhooked for around 5 years. I discovered it had no R12 in it, so being the cheap skate I am I made a quick run to the parts store and picked up around 30 bucks worth of R134. I didn't change anything except the fittings where you put the refrigerant in at. The compressor locked up on me and I discovered the clutch was completely gone. So I got a whole new compressor from the salvage yard. Since I don't want to screw up again, could someone please come up with a detailed list of what I need to replace/modify in order to do a good conversion? I would just buy some R12 or freeze12 I think its called, but I don't think you can get it in Missouri anymore. Any tips or information would be of great help.
Thanks,
Aaron
Thanks,
Aaron
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From: Virginia
You need to pull a vacuum on it. You cannot have air and moisture in the system. If it has moisture in the system, it will freeze and block the orifice and block the refrigerant flow and it won't cool.
You can get a vacuum pump pretty cheap at Harbor Freight. I just got a sale paper and you can get one for about $104. That may not seem cheap, but just go to a garage and ask them to put a vacuum on the system and see how much they charge you. And then what if something else happens and you need to open the system again?
The vacuum pump pulls all the air out, and it also makes the moisture in the system boil and turn into a vapor, and then it gets sucked out the vacuum pump.
P.S. You might as well get the guages also. They are on sale for $54.00.
Ask someone you know who has had A/C work done lately. Even with a new compressor, you are still ahead buying the other stuff.
You can get a vacuum pump pretty cheap at Harbor Freight. I just got a sale paper and you can get one for about $104. That may not seem cheap, but just go to a garage and ask them to put a vacuum on the system and see how much they charge you. And then what if something else happens and you need to open the system again?
The vacuum pump pulls all the air out, and it also makes the moisture in the system boil and turn into a vapor, and then it gets sucked out the vacuum pump.
P.S. You might as well get the guages also. They are on sale for $54.00.
Ask someone you know who has had A/C work done lately. Even with a new compressor, you are still ahead buying the other stuff.
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My understanding is that you have to: swap out ALL the hoses and associated seals, flush all the old oil out, obtain a compressor that's been rebuilt with seals which are compatible with R134a, and get a new drier. Assemble new system, fill with correct R134a compatible oil (I forget what I used..), vacuum out moisture/leak check system and if it passes, back-fill with R134a and enjoy AC that's not as good as original R12 system
I did this on my '88 Cherokee a few years back. It was not cheap, but it was then the only car I ever owned that had AC (it didn't work for the first eight years I owned it).
I did this on my '88 Cherokee a few years back. It was not cheap, but it was then the only car I ever owned that had AC (it didn't work for the first eight years I owned it).
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From: Texarkana, Arkansas
A/C conversion
I found that it is cheaper to use the R12 replacement. Enviro friendly and as others have stated you need to pull a vacuum on the system. I would also replace the dryer it cost me 28.00 at O'Reilly's last week. If you don't your probably going to end up stopping up the expansion valve and while that is not prohibitively expensive it is a job to change out. The dryer change out is a easy job and I used a leak detector and had no leaks. Put the 3 lbs 4 oz in the system and it cools just fine. If you have trouble finding the replacement R12 you can get it on Ebay. Otherwise you would proceed to convert it to R134a. Most parts houses have a kit available this time of year. But you got to change the mineral oil out of the system, the old R12 oil is not 134a friendly. 
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From: Virginia
My understanding is that you have to: swap out ALL the hoses and associated seals, flush all the old oil out, obtain a compressor that's been rebuilt with seals which are compatible with R134a, and get a new drier. Assemble new system, fill with correct R134a compatible oil (I forget what I used..), vacuum out moisture/leak check system and if it passes, back-fill with R134a and enjoy AC that's not as good as original R12 system
I did this on my '88 Cherokee a few years back. It was not cheap, but it was then the only car I ever owned that had AC (it didn't work for the first eight years I owned it).
I did this on my '88 Cherokee a few years back. It was not cheap, but it was then the only car I ever owned that had AC (it didn't work for the first eight years I owned it).
Same with the o-rings. If you want to change them out, make sure to use the r134a compatible o-rings, but if they are not leaking, leave them alone.
The old r12 oil is not compatible with the conversion kit ester oil. It won't mix with it, and won't harm it. The old oil just lays in the system and harms nothing, so you can leave it in there you do not have to flush it out.
The compressor and everything else will work also.
In the beginning the theorists thought all this stuff had to be changed, but in reality you can just stick it in and go, but NO refrigerant system will work correctly with air and moisture in it. You can't open the system and get it going again without pulling a vacuum on it.
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OK, so I have to have the worst luck ever. I just spent almost 300 bucks on a rebuilt compressor, dryer, cycle switch, orifice, and a o-ring kit. I got the dryer off with a little work and went to replace my gunk covered orifice. And it broke. I think just a small part of the top broke but I cant tell. I took some needle nose pliers to it and I think I made it worse. the wire mesh is all tore up and I'm afraid I've screwed up big time. Anyone know how to get it out and what all that gunk was around it? Please tell me I wont have to go drop another 150 for a new evaporator.
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Not uncommon, that gunk was the innards of your old compressor. Gonna need to flush the evap and condenser once we get this old bit of tube out. In the past I have used a ~3-4" long deck screw, carefully screwed into the middle of the old tube and use that to pull it, something along those lines. The alternative option is to get an "orifice tube repair kit" which is a metal tube with compression fittings on each end. You use a tubing cutter and cut out the offending section of the evap liquid line and clamp that in place, 3rd option, replace the evaporator.
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Ok, Thanks for the tip Archion and JWC 3. Tried the deck screw trick and it came right out. There is a ton of gunk all over it. I'm planning on replacing all the o rings and then getting it refilled. Should I postpone this until i get it flushed or will it be OK to go ahead and do it?
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YOU NEED TO FLUSH !!! You stand a good chance of killing that new compressor , if you don't . Flush it good , condensor , evap , lines , all of it . Make sure your condensor is not restricted internally , if it is you need to replace it also . Install all parts , dryer last , and vac down the system for 30 - 45 min. Then ck for leaks and recharge . Good luck !