73 Mach I AC Opinion

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Joined
Jul 1, 2023
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Location
Shepherdsville Ky
My Car
1973 Mustang Mach 1 Q code AC 4 speed
I hope this isn't a stupid question, but I'm looking for some opinions and or advice. My Q code Mach has factory AC and still has the Selectair compressor with R12.
The AC is blowing hot air with compressor running, so I took it to my mechanic and the compressor is worn out. To convert it to R134A, he says it needs a compressor and
all hoses as it has the original factory style hoses for R12. He's suggesting that I do nothing because the car is mostly original, which is getting hard to keep that way. He feels the value of the car
would drop dramatically with a new system. My thought is how much would the value drop with a non working system even if it would keep the originality leaving it alone.

What would you do? I don't drive it much and my first two Mach's didn't have AC, but I'm much older now. I'm leaning toward putting a new system in.
 

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My 69 t-bird had been converted from r12 to r134 or whatever it is using what looks like the original compressor. I believe there's a table they use to convert the old required weight of r12 into the required weight of the new stuff.

As far as the other part of the question, what do you care more about? Driving the car and enjoying it or hurting the potential value for the next guy who will own it? I say screw the next guy. Do whatever it is that makes you happiest. Keep the original parts in a box and the next guy can put them back on if he wants.

1694046216570.png
 
Take your car to another mechanic. Either have it repaired and recharged with R12 or converted to R134. The conversion only requires draining and flushing the system, changing the o-rings to R134 compatible ones, change the receiver/dryer, and charging it with the 134. No need to change the hoses or compressor as long as they're in good condition.
The York style compressor on your car will work with R134 and you can simply replace it, if yours is bad. They run $150-$200. Many people replace the York style with the more efficient (less load on the engine) rotary style Sanden compressor. This is optional, though, when converting to R134.
 
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I had a '68 Mustang with air, and I replaced the hoses and dryer with the higher pressure ones for R134. I figured changing hoses and dryer on a 50 year old car was a maintenance item regardless, so going to the higher pressure ones was no big deal. I rebuilt my stock compressor, but had to install adapters for charging with R134, IIRC. It worked fine. A lot of people convert to the newer compressor, and I think as long as you save the original unit, it's not a big deal.
 
From my understanding, the molecules that make up R134a are smaller than those of R12, which can cause leaks through the original hoses. You could let it ride, or send the hose assemblies out to be rebuilt with new hose. There are companies that do this work, such as Cold Hose. You might even have a place local, might be worth a Google search.

https://coldhose.com/
NPD also offers reproduction hoses

https://www.npdlink.com/1965-1973-m...oses-rigid-tubes-valves-and-related?year=1973
Compressors are available new or reman. Advance Auto sells reman Yorks for $125 and up.
 
Based on the picture you posted it seems you value originality. Take Hemi's suggestion and put on a new compressor and filter/drier. If you want really cold AC, bite the bullet and recharge it with R-12. I've never seen a 134a conversion blow air colder than 50 degrees. If you convert to 134a many suggest a larger/more efficient condenser. Good luck with whatever you decide to do. Chuck
 
Take your car to another mechanic. Either have it repaired and recharged with R12 or converted to R134. The conversion only requires draining and flushing the system, changing the o-rings to R134 compatible ones, change the receiver/dryer, and charging it with the 134. No need to change the hoses or compressor as long as they're in good condition.
The York style compressor on your car will work with R134 and you can simply replace it, if yours is bad. They run $150-$200. Many people replace the York style with the more efficient (less load on the engine) rotary style Sanden compressor. This is optional, though, when converting to R134.
Okay thank you.
 
Based on the picture you posted it seems you value originality. Take Hemi's suggestion and put on a new compressor and filter/drier. If you want really cold AC, bite the bullet and recharge it with R-12. I've never seen a 134a conversion blow air colder than 50 degrees. If you convert to 134a many suggest a larger/more efficient condenser. Good luck with whatever you decide to do. Chuck
Thanks Chuck
 
From my understanding, the molecules that make up R134a are smaller than those of R12, which can cause leaks through the original hoses. You could let it ride, or send the hose assemblies out to be rebuilt with new hose. There are companies that do this work, such as Cold Hose. You might even have a place local, might be worth a Google search.

https://coldhose.com/
NPD also offers reproduction hoses

https://www.npdlink.com/1965-1973-m...oses-rigid-tubes-valves-and-related?year=1973
Compressors are available new or reman. Advance Auto sells reman Yorks for $125 and up.
Great thanks.
 
Our 73 Mustangs were both non-A/C cars. I added Classic Air A/C kits on both, which uses R134. I was skeptical at first about how well the R134 would work, but it does a fine job. You ought to be able to covert to R134 just fine, but you must remove any and all of the R-12 compatible refrigerant oil, and replace it with R134 compatible refrigerant oil. The two types of oil are not interchangeable, nor will they mix properly. Be sure to properly evacuate the AC system with a refrigerant pump, otherwise you ran a risk damage to the system. Whenever I open up our AC system I replace the Receiver/Dryer also.

Here is the web site number for Original Air:

https://www.originalair.com/
 
I would prefer to have a car with operational A/C. I don't think it would adversely affect value. In Australia it wouldn't.
The hoses can be inspected and only replaced if necessary.
Get the compressor checked and repaired (front seal head/valves) or replace. Ensure the correct oil is used (Pag or Ester).
Flush the entire system.
Fit new R134a Thermal Expansion Valve.
Fit new receiver drier.
Change all O rings.
The charge rate for R134a is about 80% of what the R12 quantity was. Check pressures when charging.
 
Our 73 Mustangs were both non-A/C cars. I added Classic Air A/C kits on both, which uses R134. I was skeptical at first about how well the R134 would work, but it does a fine job. You ought to be able to covert to R134 just fine, but you must remove any and all of the R-12 compatible refrigerant oil, and replace it with R134 compatible refrigerant oil. The two types of oil are not interchangeable, nor will they mix properly. Be sure to properly evacuate the AC system with a refrigerant pump, otherwise you ran a risk damage to the system. Whenever I open up our AC system I replace the Receiver/Dryer also.

Here is the web site number for Original Air:

https://www.originalair.com/
I appreciate the info.
 
I would prefer to have a car with operational A/C. I don't think it would adversely affect value. In Australia it wouldn't.
The hoses can be inspected and only replaced if necessary.
Get the compressor checked and repaired (front seal head/valves) or replace. Ensure the correct oil is used (Pag or Ester).
Flush the entire system.
Fit new R134a Thermal Expansion Valve.
Fit new receiver drier.
Change all O rings.
The charge rate for R134a is about 80% of what the R12 quantity was. Check pressures when charging.
I agree. I can't imagine a non working factory AC system will hold the cars value more than a working AC system.
 
I have been considering the same thing on my 72 Convertible. I was looking on line for available options and found this stuff that claims to be a direct replacement for R-12. I first read about it on a blog from another car site and several people swore by it as a quality product and some had been using it for years. Might be a good and cost effective option to look into. Anybody have any experience with it?
 

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I have been considering changing mine to r134 and decided to try to keep it stock but it will require buying a new old style compressor as mine is locked up. Mine is very original and I prefer keeping it that way. Just depends on your preference. I would recommend doing which ever one makes you happy. Good luck.
 

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