A/C rebuild tips

Did you use the hot temp area(105 degrees+) orifice tube or just the standard one?
 
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I used the "blue" tube that came with the adapter. I found the blue tube in the crimped liquid line that I cut out.... so I used it. I have seen red , white , blue in other cars but don't know what for. I just posted an example as done that to the thread.
 
A/C rebuild completed today

This thread was great information for rebuilding my air conditioner. Falcon20x has provided a wonderful resource. Better than shop manual etc. The tip from TBirdSCFan to adjust the pressure switch to 20 psi for R134 is awesome. Also appreciated the suggestions for where to add oil and how much. I wish that I had added oil as recommended in this forum when I previously reassembled A/C during motor swap and converting to R134. Might have avoided recent compressor seizing that required this A/C rebuild today.

In addition to ordering compressor, accumulator, and liquid line with orifice tube from Rock Auto I also ordered Motorcraft o-ring set (YF982) but didn't need any of them. The compressor came with two O-rings installed, the accumulator came with O-rings installed and a bag of O-rings, and the liquid line came with O-rings installed and a bag of O-rings.

The flush kit from Autozone worked perfectly. Rather than using a female chuck I removed the valve stem connector from top of tank and replaced with a male plug quick disconnect coupler to connect air hose to. When complete I R&R connector to return it with original valve stem connector. Was funny that gentleman at Autozone said they didn't have an A/C flush kit until I convinced him that their web site said they did have in loan-a-tool. He went in back and came out with a virgin flush kit that had never been used and a quart bottle of flush solvent.

I was confused by multiple oil viscosity to choose from. Nothing in this forum, other forum, or shop manual has specification for viscosity but Autozone had three viscosity (low, medium, & high). Sales dude recommended medium if don't know which to use.

Next to vacuum out, charge with R134, and adjust pressure switch.
 
I was confused by multiple oil viscosity to choose from. Nothing in this forum, other forum, or shop manual has specification for viscosity but Autozone had three viscosity (low, medium, & high). Sales dude recommended medium if don't know which to use.
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I recall using PAG46 for 134a. The compressor came with a note on how many ounces to add. Like ending up with more than enough 0-rings, note if any other oil is added to your 134a and/or to the compressor when shipped.

See https://www.rtitech.com/downloads/News/Oil Chart - Compressor.pdf

...compressor type is Ford FS10.
 
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The flush kit from Autozone worked perfectly. Rather than using a female chuck I removed the valve stem connector from top of tank and replaced with a male plug quick disconnect coupler to connect air hose to. When complete I R&R connector to return it with original valve stem connector. Was funny that gentleman at Autozone said they didn't have an A/C flush kit until I convinced him that their web site said they did have in loan-a-tool. He went in back and came out with a virgin flush kit that had never been used and a quart bottle of flush solvent.

I was confused by multiple oil viscosity to choose from. Nothing in this forum, other forum, or shop manual has specification for viscosity but Autozone had three viscosity (low, medium, & high). Sales dude recommended medium if don't know which to use.

Next to vacuum out, charge with R134, and adjust pressure switch.

Same thing happened to me:confused:. Autozone had no idea they had one for rent, I even had to explain to them how to use it.

PAG 46 is what my compressor came pre filled with. Everything I read about R 134 and oil points toward PAG 46 as the default oil to use.
 
Pag 46 oil

Same thing happened to me:confused:. Autozone had no idea they had one for rent, I even had to explain to them how to use it.

PAG 46 is what my compressor came pre filled with. Everything I read about R 134 and oil points toward PAG 46 as the default oil to use.

Now I understand. PAG 46/100/150 is low/medium/high viscosity
 
I'm of the opinion it's worthwhile to continue using the R12, even though it's more than R134. The actual price of the gas is pretty menial, a can of R134 is about $12 and a can of old stock R12 goes for around $40 a can, I'd pay that extra premium all day to have better cooling, the difference in price for a full system is a little more than a single tank of gas. And if you have the R12 already in the system, you can recover it. For something you're likely to be using for a decade, it's worth it to me.

All the nonsense that goes along with a conversion just doesn't seem worthwhile with the flushing and incompatible oils, higher pressures, having to install parallel flow condensors, new orifice, etc. To really do it right, many cars require all new AC hoses. You can almost make the case it's cheaper to pay more or the R12 than convert to the cheaper R134.

I had a car converted to R134 from R12 (but not a Thunderbird), and it just never cooled that well. It was done by a pro, and it was in the era when r12 prices had gone through the roof, which is why I did the conversion. I had a 2nd AC pro take a look and he basically said that's as good as its going to get. It was about 70 degrees at the vents, it just kept you from sweating, didn't really cool the car down. I even added auxilary electric fans to help.

I know AC pros get mad at hearing this, but I'd also look into using Hydrocarbon refrigerants as a substitute for R12, brands like Freeze 12, DuraCool, Envirosafe, HotShot, etc. It's basically just Propane with the moisture taken out. I have a good friend that was a Ford Master Mechanic and he was a fan of them as a substitute.
 
70 degree vent temps... dude... you been scammed LOL!! Thats someone who is just too lazy or doesn't know what he's doing and is passing off BS to get his pay and move on.. :rolleyes::rolleyes:

Sure.. the original refrigerant is the best thing to use, but... since you have to have a license and its hard to procure, using r134a is a reasonable tradeoff. And no.. it doesn't work as well IF you JUST drop it in and do nothing more. You sort of have to "adjust" your old A/C like we discussed. I hit the sweet spot in my red car.. new modern multipass condenser (the OEM tube&fin one will not do the job), new (or adjusted) pressure switch, orange Otube, and charged just right. I get 34 out the vent on recirc. :cool:

Now here's the conumdrum.. IF... and its a big IF... your system is leakfree and in good condition, you would never have lost cooling in the first place.. So its (therefore) broken by definition. You must repair it. For most of the time though, you never have the chance to repair before the compressor goes. When the compressor goes it suffers what is called black death. You essentially have to replace everything under the hood to fix it. This means a new condenser which is only made in the modern 8mm multipass type, compressor, liquid line, and accumulator. Since you have to do all of that anyway even if you stay with R12, making the jump to r134 is not that much more work.

As for HCs.. I might be willing to consider it, but I honestly don't have time to mess with experimenting with it.. so I stick with what has a track record. BTW.. of your list... only Duracool, Envirosafe are actual HC refrigerants.. 2 are r134 blends. Freeze 12 for instance.. the number 12 means well..... it means 12! .. has nothing to do with R12 its purely a labeling gimic. :rolleyes:
 
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Seems to me that many of us lost our R-12 because the stock O-rings seem to give up if you let the car sit for more than a couple of months. Or the compressor died, which would require a flush and/or parts replacement. So I think most people will be stuck buying new refrigerant in any case.

Still, I do basically agree that the R-12 is not so much harder to get or more expensive that I would automatically jump to R-134a. (I got my Mobile AC certification so I can buy all that stuff now! :D)
 
70 degree vent temps... dude... you been scammed LOL!! Thats someone who is just too lazy or doesn't know what he's doing and is passing off BS to get his pay and move on.. :rolleyes::rolleyes:

Sure.. the original refrigerant is the best thing to use, but... since you have to have a license and its hard to procure, using r134a is a reasonable tradeoff. And no.. it doesn't work as well IF you JUST drop it in and do nothing more. You sort of have to "adjust" your old A/C like we discussed. I hit the sweet spot in my red car.. new modern multipass condenser (the OEM tube&fin one will not do the job), new (or adjusted) pressure switch, orange Otube, and charged just right. I get 34 out the vent on recirc. :cool:

Now here's the conumdrum.. IF... and its a big IF... your system is leakfree and in good condition, you would never have lost cooling in the first place.. So its (therefore) broken by definition. You must repair it. For most of the time though, you never have the chance to repair before the compressor goes. When the compressor goes it suffers what is called black death. You essentially have to replace everything under the hood to fix it. This means a new condenser which is only made in the modern 8mm multipass type, compressor, liquid line, and accumulator. Since you have to do all of that anyway even if you stay with R12, making the jump to r134 is not that much more work.

As for HCs.. I might be willing to consider it, but I honestly don't have time to mess with experimenting with it.. so I stick with what has a track record. BTW.. of your list... only Duracool, Envirosafe are actual HC refrigerants.. 2 are r134 blends. Freeze 12 for instance.. the number 12 means well..... it means 12! .. has nothing to do with R12 its purely a labeling gimic. :rolleyes:

It wasn't a matter of being scammed, they were working with the equipment the car had, you have to make upgrades to get the R-134 to get R12 performance just like the OEMs did when they made the switch, and I'm also dealing with severe 110 degree heat (AZ). In most climates in the US, the conversion would have been fine. This was also the very early days of R-134, parallel flow condensors as an upgrade weren't as universally available to retrofits.

If you're planning on rebuilding nearly everything and making upgrades to the condenser, rerouting lines, etc, then it probably makes sense to go with R-134, but if it's something like your system needs a leak repaired and recharge, I would repair and refill with either R-12 or look at the hydrocarbon route. Even though the old stock R-12 looks expensive, as long as you have a system that doesn't leak, it's not that much more than filling up your tank at the gas station.

R-12 just worked a lot better for car AC, and it was a bullsh#t the reason it got banned the way it did, it was a combination of junk environmental science and new patents. Now they're saying R-134 is bad for the environment just about the time the patents are all expiring and there's a push to ban it. How convenient.

It was very easy to get ice cubes to come out of your vents with an R-12 system. Cars in that era never seemed to have issues cooling, but I've owned new cars from the factory with R-134 and some still have issues. If you live in a really hot climate, I would probably just pay the extra for the R-12 just to get the better performance and reuse as much of the factory setup as possible. Or look into the hydrocarbons. I would only go with R-134 if I had to, but really cold AC is important to me.
 
i've been searching for a while and cant find the PN for the 94-95 motorcraft cycle switch. I know I saw it somewhere in the forum but now can't find! Not coming up in Rock auto either.

Do any of you gents have it handy?
 

Heya Falcon...or anyone with the knowledge. Your link (although expired) sends me to an auction for a Santech Industries #MT2907 kit. Is this the one you used?

I used the compatibility tool on ebay and also checked the part number in autozone and in both places it said it was not compatible with the car. In this case, I entered a 90 SC since that's what I'm currently working on.

I just wanted to confirm that that's the kit you used so I can buy it.

Thanks!
 
There are some differences though. I got a set of retrofit fittings from a BMW friend and only the low side worked. Then I bough an A/C Pro retrofit kit PN LXVC-12, which comes with three fittings. Two fit perfectly and one is the same as the kit I got from my BMW buddy. Unfortunately, I didn't notice that the A/C pro kit doesn't come with valves so I have to go get a valve.

Just FYI, Santec PN MT4031 appears to be the right kit with both correct metal fitings, and it comes with valves and plastic colored caps. That's the one I would get, would I need to do this again.
 
hey question, got a accumulator stuck to the evaporator.
yea i have the right tools (seasoned ac tech)
any tricks to get it to give up it's charms?

all of the rest of the lines came right out!
only 18 k miles on this sc... yea it is 2021! lol!
leaking at the orings due to age.
 
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