AC conversion

MiJBV1990SC

Registered User
Hello To All!!

I JUST got a 91 SC :) and am a complete Newbie to these cars. The car needs to have the AC recharged. This Requires a conversion from the old system (r12 I think) To the New (r134 or somthing) am I right on this??? If so how complicated is this and how costly? Better to have a dealer do it?? Thanks for your help.
 
MiJBV1990SC said:
Hello To All!!

I JUST got a 91 SC :) and am a complete Newbie to these cars. The car needs to have the AC recharged. This Requires a conversion from the old system (r12 I think). To the New (r134 or somthing) am I right on this??? If so how complicated is this and how costly? Better to have a dealer do it?? Thanks for your help.
You can still get the R12 refilled at some places but it is very expensive. Around $5 per ounce last I checked and you need 42 oz. I think. Most places will convert it to R134 which will be cheaper in the long run. I was quoted $200 at one place before I decided to ditch my AC altogether. You should have it serviced by a shop and have the evaporator canister replaced as well as new seals and O- rings. Otherwise you run the risk of having leaks with the R134.
 
I went to napa and bought the cheap kit to convert to 134 and had no problems except for finding out the condenser had a leak in it and thats why it stopped working, but the air worked for awhile
 
defect said:
I went to napa and bought the cheap kit to convert to 134 and had no problems except for finding out the condenser had a leak in it and thats why it stopped working, but the air worked for awhile
This is why I try to discourage people from using the store kits. What you just described happens quite a lot. When/if you decide to repair it again, it will cost more than it would have. I'd suggest reading up on the topic and then making your choice about how to proceed.

I try to let people know what the problems can be with quick and cheaper kits. Being in Texas, I decided when repairing my A/C to spend what was needed to do it right and have it last. The repair kit sellers know this stuff, but they're trying to fill a market demand for low $ refrigerant and doing business. The fine print in the instruction book covers that. ;)

BTW, what I'm trying to say is your compressor is toast and you're looking at a minimum of $500-$600 to fix it again. You can get by with about $300 if you go with used parts, but even that has it watch-out fors.
 
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I have a 90 SC 5-speed. I am in the same boat as you. I have to recharge my A/C, but I have to replace the high pressure hose prior to having it recharged. If you use the "search" option you can look up information about the A/C, and then decide which route you'd like to go. I looked at my options and decided to stay with R-12. So now that i decided that, I am going to order the high pressure and low pressure hoses from the dealer. and will replace all the remaining O-rings in the system. I went to some shops and the best price I have gotten so far is $45/lb of R-12 and $50/Hr of labor. Basically i am looking at (2.5lbs x 45) + 50 + (Hi Press. Hose) + (Low Press. Hose) + (O-rings) = COOOOOOOOOOL A/C :)
I hope this helps, and congratulations on your new purchase..
Good Luck
:)
 
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TbirdSCFan said:
This is why I try to discourage people from using the store kits. What you just described happens quite a lot. When/if you decide to repair it again, it will cost more than it would have. I'd suggest reading up on the topic and then making your choice about how to proceed.

I try to let people know what the problems can be with quick and cheaper kits. Being in Texas, I decided when repairing my A/C to spend what was needed to do it right and have it last. The repair kit sellers know this stuff, but they're trying to fill a market demand for low $ refrigerant and doing business. The fine print in the instruction book covers that. ;)

BTW, what I'm trying to say is your compressor is toast and you're looking at a minimum of $500-$600 to fix it again. You can get by with about $300 if you go with used parts, but even that has it watch-out fors.

Most lube shops have facilities to do the evacuations and pressure test when converting to R134a. Basically R12 is being fazed out. That's why it's so expensive. If your system is just dry due to age then you can get it done without repairs. Call around and get a price and specify that you need to be converted and pressure tested. You should specify that they leak test it. If it leaks a can of sealer will possibly do the trick unless you have major problems.
When I had mine done I went early in the AM when they weren't very busy and watched while they added the R134a. Mine's been three years and its fine. Cost me $200.00.

Oh BTW, R134a doesn't cool as well as R12 but it should be enough to get you through most hot weather.
 
TbirdSCFan said:
This is why I try to discourage people from using the store kits. What you just described happens quite a lot. When/if you decide to repair it again, it will cost more than it would have. I'd suggest reading up on the topic and then making your choice about how to proceed.

I try to let people know what the problems can be with quick and cheaper kits. Being in Texas, I decided when repairing my A/C to spend what was needed to do it right and have it last. The repair kit sellers know this stuff, but they're trying to fill a market demand for low $ refrigerant and doing business. The fine print in the instruction book covers that. ;)

BTW, what I'm trying to say is your compressor is toast and you're looking at a minimum of $500-$600 to fix it again. You can get by with about $300 if you go with used parts, but even that has it watch-out fors.

I knew this wasn't the best way to go, but it was not working for 4 years and I figured the compressor was shot anyways so I figured what the heck
 
The best way to go is a new a/c compressor, rec drier and the liquid line. You can buy all the parts from NAPA, and it wont cost you over $300 bucks. The new o-rings, replace them all, replace the drier and liquid line, flush the condenser with compressed air and brake clean and evac and charge. It will be well worth it in the long run. The liquid line is $20 bucks from Ford. Most of the Ford R12 FS10 compressors are not very-conversion friendly and usually blow up down the road. Some here have done it and been lucky, but 8 out of 10 times the compressor will grenade after a conversion.
 
unclenick said:
The best way to go is a new a/c compressor, rec drier and the liquid line. You can buy all the parts from NAPA, and it wont cost you over $300 bucks. The new o-rings, replace them all, replace the drier and liquid line, flush the condenser with compressed air and brake clean and evac and charge. It will be well worth it in the long run. The liquid line is $20 bucks from Ford. Most of the Ford R12 FS10 compressors are not very-conversion friendly and usually blow up down the road. Some here have done it and been lucky, but 8 out of 10 times the compressor will grenade after a conversion.
Prices have dropped some in the past few years and there are some really good deals on packages on ebay.. No one knows how well a used compressor will stand up. A lot of it has do with how long it was run when low on refrigerant and hence.. low on oil. The internal dry wear is what will cause them to barf when they are put back in service.. r134 only increases the stress, but r12 will cause it too. I'll attach some picture that illustrate what I'm talking about.

A new one, if properly installed will stand up just fine for years and years.. My FS10 runs at near 300 on a real hot day and is over 3 years old. Also, keep in mind that a restrictive or low efficieny condenser, or a clogged Otube will greatly increase running pressures and overwork the compressor. To make it work better and decrease the stress, you really need to replace the OEM condenser with at least a newer serpentine or parallel flow type.

Here's what happens when a leak develops and isn't repaired properly. That is to say, when the oil goes out and isn't replaced promptly and air seeps in, it won't matter what you recharge it with as the damage is done.

The first shot shows where the cylinder has rust and buildup and has pitted. Keep in mind A/C is a closed system. When normal, every part of the inside is normally coated with a thin layer of oil. There should never be any internal corrosion. When a leak develops, the clock starts ticking on its tombstone. This pic shows what happens when air and moisture get in and oil isn't replaced. (A repair shop was responsible for this BTW).

The second picture shows the cylinders and the pistons in their normal condition. The 3rd picture shows more rust damage to the reed plates from air/moisture and lack of oil. Note the black teflon ring debris from a failed piston seal. This is part of what composes the "black death" debris which will get pushed into the condenser and clog the Otube. There are also metal shavings which this picture doesn't show. This is why flushing is essential to fixing it right. :)
 
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i mostly just get the kit for about 30 bucks with the fittings and oil . if you think you have a leak that superseal from walmart works much better than most leak stoppers ive tried its about 20 bucks in a yellow can
 
NMxr7SC said:
there's a new compressor for 140 on Ebay right now. Search under "thunderbird"
I did see that. Also I need to replace my head gaskets to even get the car running right first. I was just wondering what I needed to do to get the AC working again once the car runs. Thanks for all your help. Keep opening the hood to look at were to get started on the Head gaskets and think :eek: :confused: :mad: May be in over my head on this one!!!

Thanks for all your help

P.S. are there any books I can buy that will help guide me through doing these gaskets??
 
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