A/C Parts Needed for 134a conversion

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Joined
Jan 25, 2017
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Location
Tavares, fl
My Car
71 Mustang Mach 1
302-2v
C4

I just got my Mustang a couple of weeks ago and not much is known about what has or has not been done to it.  The A/C system is very questionable.  It doesnt blow very cold at all.  The service ports on the compressor look like one has a 134a fitting on it and the other has the R12 fitting on it.  I am trying to determine if it has been converted or not, or if someone just threw a fitting on there and dumped a can of A/C PRO in it so that it would work long enough for them to sell it.  So my main question is, are there any markings on the hoses that show they are for 134 or R 12?  Is the expansion valve different?  I have seen in some posts where the expansion valve is inside the air box and has a probe that goes down into the core.  Mine is mounted on the line in the engine compartment and looks like the picture below......



Here is a pic of the service ports.



all the hoses are painted:( so hopefully only the top is painted. 

The clutch seems to work fine and the compressor too, so hopefully that will be ok for a while.  At some point I suppose I will convert to the sanden style compressor.

Looking on the Original Air site, they dont specifically state if any of their parts are for 134a or R-12 for the most part at least.  Which is kind of annoying.  I know the original R-12 hoses wont take the pressure that the 134a runs at, and you need the inner core type of lines.  They dont specify that on their site, so I am wondering if all their lines are 134a compatible and can be used on either R12 or 134a which would make sense.  I just wish they would tell you either way.  Same for the expansion valve.  Im pretty sure the orifice size is different since it is on my Bronco.  But they dont say anything about that either.

Any help would be great.  I just want to be able to ask intelligent questions when I get them on the phone.

 
When I asked the questions you have I was told all that had to change was the o-rings to the ones made for the 134. I have changed mine and I was told to get an new canister to go out front since it acts as the filter. The expansion valve on all I have seen is on the outside. I took the entire system apart and cleaned and put new lube in the compressor also. I am actually going to use another type refrigerant called DuraCool out of Canada. They say less pressure and takes a lot less to fill the system also.

 http://www.duracool.com/

I had hoped to get it going this week but electrical bugs have kept me from getting the engine going. This car sat for 26 years.

I cannot say good or bad about the duracool when engine is running I will vac the system and fill and see how it goes.

BTW po had painted all the hoses on my system and I stripped off back to the original hoses and lines so it looks much better.





temporary image upload

 
Any suggestions on how to flush the system with a A/C Flushing solvent?

I suppose the best thing to do is to disconnect the lines from the dryer, make one the inlet and the other the outlet. Put the outlet into a bucket or something, and Use my transfer pump to pump the flushing fluid thru the system. I just dont know if the compressor needs to be turned while flushing it or not.

As far as a flushing agent goes, Napa has a quart for $13 which is alot cheaper than some other places I have seen.



So to do the flush, I guess I should remove the compressor first, and drain out all the oil. Then put it back on, and connect the lines, then run the flushing solvent thru. I dont have my air compressor hooked up since this house has no 220 outlet in the garage, so I am hoping I can just pump it thru with a hand pump.

How much flushing solvent should I run thru it?

 
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A word about Duracool, it is a very pure and dry isobutane/propane mixture. So, use caution when connecting, charging, removing, etc. No open flames, smoking, sparks and so on allowed. It is prohibited for use in motor vehicles in some countries due to this. I believe that is ridiculous, the small amount of it that is used is insignificant compared to the potential fire/explosive hazard of a tank of gasoline. Even antifreeze sprayed onto a hot exhaust manifold has the potential of igniting.

It has a much lower ozone depleting/global warming potential than R134a while being more efficient, for those that are concerned about such issues.

 
I took a picture of my expansion valve. I was just wondering what this canister with the blue cap on it is. and what the silver air line is going to the intake. Is the canister some kind of filter?



 
jowens1126, our era Mustangs used the block type expansion valve as in your illustration. Later Ford products in the late 70's transitioned to a POA type valve. The device with a probe on it is the thermostat for the evaporator temperature control.

With a lot of half a$$ repairs done by PO's and make believe mechanics, your best bet is to treat your system like a R-134 conversion was never done.

Our shop used FJC conversion parts since Ford did not offer any R-134 conversion parts. A label was always applied under hood indicating the R-134 conversion and the new charge levels. The lines were never replaced unless defective. Since the R-134 did operate at a higher pressure the systems were charged at 75-80% of the original R-12 charge. The system used a PAG type oil and the receiver/dryer was changed since it was basically the filter on our style cars unlike the orifice type on new model cars. After a system flush and new R-134 and PAG oil compatible o rings were installed the system was charged and unless there were other component problems, you had cold air.

I'm sure others here have already been through this process and can add more info than I have.

Good luck with your project!

 
jowens1126, I am a slow "Hunt and Peck" typist. So by the time I finished my previous post I had missed your question about the canister.

That is what Ford called a fuel vapor storage canister and has a charcoal type material inside. The rubber line running from it attaches to a metal line that runs to the fuel tank to a fuel vapor valve in the top of the tank. The corrugated hose attaches to a stub on the side of the air cleaner. The canister stores fuel vapor from the tank and when the engine is started the vapor is pulled through the air cleaner into the combustion chamber where it is burnt.

Early stages of emissions control. If folks back then only had an ideal of what would be on these cars in 2017!

 
Thank you for that Information Steve, Im also going to get the conversion label and place it in the proper place. That way everyone will know in the future.

I was wondering if thats what that canister was. Im very familiar with 90's Era EFI Fords, but this is my first ever 70's carburated vehicle.

As far as the conversion goes, Which fittings have O-rings? Do they all? I suppose I need the Green O rings like came with my compressor for my 94 bronco. I will have to go look and see if theres a O-ring kit somewhere, and the other parts so I can put together a part order today.

Parts,

O-ring kit - I think I still have them all from my Bronco A/C kit. I think they are all the same size.

Dryer

Flushing Solvent

2 cans 134a

I also found these service ports on Ebay, Theres a #8 and a #10. I suppose one is the high side and one the low side?

#8 size

http://www.ebay.com/itm/YORK-ROTOLOCK-A-C-COMPRESSOR-FITTING-W-13MM-134A-PORT-8-O-RING-TEFLON-RING-/311682295968?hash=item4891b668a0



#10 size

http://www.ebay.com/itm/YORK-ROTOLOCK-A-C-COMPRESSOR-FITTING-W-13MM-134A-PORT-10-O-RING-TEFLON-RNG-/400808853186?hash=item5d5211bec2



So What is the normal charge for R-12? (1.5lbs??) How much 134a should I put in the system? (70-80% of R12 charge?)

 
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got all my parts on order for the next set of projects.  Looks like next weekend will be a busy one.  I still havnt worked on it at all today, but I have made lots of progress cleaning out the garage and clearing my work bench and putting all my tools back in the tool box.  So that is a big plus.  It was such a mess in there from the last 2 months when I had my bronco interior completely removed to rewire everything.  That was a major undertaking.  So hopefully now that the afternoon thunderstorm is done, I can get back in there and finish up the garage and start on my seat belt conversion.

I watched a few videos on A/C system flushing and I think I know what Im doing now.  You cant flush the compressor, so I will just pull it and suspend it over a bucket overnight and let all the old oil drain out of it.  Give it a few turns by hand to help dislodge all the oil out periodically and that should be good.  Then I have to pull the condenser and I will flush it separately.  I am going to have to find a way to hook my compressor back up, so I may have to go to lowes and get some 10/12 romex and make me a stout extension cord so I can plug it into the dryer outlet in the laundry room off the garage.  That will get me in business again.  Then I will take all of the hoses off and flush them one at a time, replace all the O-rings, and try to get all the paint off of them.  Then I will flush the evaporator and I should be good to go.  I am going to just replace the expansion valve since they are cheap.

I also ordered a flushing gun and flushing solvent. Should be a fun project.

So That should get me back in the cooling game again.  I already have a vacuum pump and Hose set so I will be all set.

 
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Thank you for that  Information Steve,  Im also going to get the conversion label and place it in the proper place.  That way everyone will know in the future.

I was wondering if thats what that canister was.  Im very familiar with 90's Era EFI Fords, but this is my first ever 70's carburated vehicle.  

As far as the conversion goes, Which fittings have O-rings?  Do they all?  I suppose I need the Green O rings like came with my compressor for my 94 bronco.  I will have to go look and see if theres a O-ring kit somewhere, and the other parts so I can put together a part order today.

Parts,

O-ring kit - I think I still have them all from my Bronco A/C kit.  I think they are all the same size.

Dryer

Flushing Solvent

2 cans 134a

I also found these service ports on Ebay, Theres a #8 and a #10.  I suppose one is the high side and one the low side?

#8 size

http://www.ebay.com/itm/YORK-ROTOLOCK-A-C-COMPRESSOR-FITTING-W-13MM-134A-PORT-8-O-RING-TEFLON-RING-/311682295968?hash=item4891b668a0



#10 size

http://www.ebay.com/itm/YORK-ROTOLOCK-A-C-COMPRESSOR-FITTING-W-13MM-134A-PORT-10-O-RING-TEFLON-RNG-/400808853186?hash=item5d5211bec2



So What is the normal charge for R-12? (1.5lbs??) How much 134a should I put in the system? (70-80% of R12 charge?)
You can get the o-rings at any parts house the standard assortment has all you need and more. I found some corrosion inside lines and cleaned with round wire brushes. Right or wrong I cleaned mine with soap and water and let dry before install. The Duracool works at lower pressure is one reason I am trying it. You do not need to change the lines. I also cleaned all the connections with fine steel wool to give the o-rings a good place to seal. I got engine running this afternoon may put a temp gas tank on and do the air conditioner tomorrow with the Duracool. I will post if I do.

 
I really enjoy working on these older cars. Its a pleasure since they are all fairly simple mechanical systems. I just wish I had room to tear it completely apart and blast and paint the body and every piece. Maybe one of these days. Im enjoying the hell out of driving this car, and so is my son. I dont even really mind the manual drum brakes. But that will change shortly, I ordered a new radiator today, and a vacuum brake booster, and a oil pan gasket and valve cover gaskets. So A/C, Brake Booster, Radiator, clean the engine, replace the oil pan gasket and valve cover gaskets. I think that will take a couple of weekends to get all this done.

Ive never done the oil pan gasket in a car before. I did one on my bronco but the engine was on an engine stand at the time. So it should be interesting to say the least. Fortunately its a front sump pan and should be simple to get out. Its practically impossible to do it in the bronco with the engine in the truck. Hopefully I dont have too many issues with that one.

 
jowens1126, The amount of R-134 Freon depends on the info from the manufacture of the Conversion kit/parts that you are using.  FJC came to our shop and set up everything we needed as far as parts and literature, so all the techs had the conversion charts to determine what the R-134 Freon charge would be vs the R-12 charge. The label placement for the factory R-12 charge for our Mustangs is normally on the top of the radiator support as in David's under hood shot of his vert. That label indicates the factory R-12 capacity that will have to be known to determine what percentage of that will be needed in R-134.

Your last sentence answered one of my thoughts about making sure to pull a complete vacuum on your system once you have put it back together. If not, you'll be repeating your AC repairs again!  

At this time I'm out of state and away from my cars and most of my info but I believe the label I posted reflects the 1lb 12oz that was the R-12 capacity of our Mustangs.

Let us know how everything goes and remember there is no such thing as stupid questions here.....only expensive mistakes!!

r12 label.jpg

 
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Thanks for all your help Steve.  Im new to mustangs, but not to fords or forums.  I am a Moderator over on Fullsizebronco.com.  Ive been on that site for 6 or 7 years now sharing what I have learned about working on Bronco's.  My build thread over there is the #1 or #2 build thread on the forum depending on the day.  Currently its at 182,126 views.  Ive done alot of work to that truck and learned alot of what I know from my experiences working on it.  I always document the hell out of everything I do if possible.  I also make sure I research everything fully before I start working, so I know exactly the proper way to do any job.  There is nothing worse than going back and fixing someone else's half ass work.  I do it right the 1st time or I dont do it at all.

I suppose I should have looked a bit more carefully. lol  I have the sticker right where its supposed to be.



photos uploader

 
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jowens1126, don't want to get carried away and hijack your AC thread, just wanted to say glad to have someone with your Ford background to join us here. You know better than anyone how insanely popular all the Bronco's are, especially the full size. (OJ model included)! Our body shop manager had several of the first generation, two full size (79 & 96), and a Bronco II. They were tougher than nails to stand up to him, as he drove them as hard as possible. Now....we have our own personal go to person for Bronco questions and info!   :D

 
When I asked the questions you have I was told all that had to change was the o-rings to the ones made for the 134. I have changed mine and I was told to get an new canister to go out front since it acts as the filter. The expansion valve on all I have seen is on the outside. I took the entire system apart and cleaned and put new lube in the compressor also. I am actually going to use another type refrigerant called DuraCool out of Canada. They say less pressure and takes a lot less to fill the system also.

 http://www.duracool.com/

I had hoped to get it going this week but electrical bugs have kept me from getting the engine going. This car sat for 26 years.

I cannot say good or bad about the duracool when engine is running I will vac the system and fill and see how it goes.

BTW po had painted all the hoses on my system and I stripped off back to the original hoses and lines so it looks much better.





temporary image upload
Duracool and RedTek are non-approved hydrocarbon based products, also known generically as R-12a or HC-12a. R-12a is completely compatible with the hoses and oils used in R-12 systems. I know a few folks using it in their 80s and 90s cars as a replacement for R12 without having to do any conversion as you would need to do for 134a and they seem happy with it and how well it cools. Sounds like a great alternative and you can buy it on Amazon. 

That said, I am no chemist nor am I an A/C systems expert, but from what I have read I am very leery of R-12a as it is essentially a hydrocarbon and highly combustible, much like Propane. A leak in the system into either your engine or passenger compartment could lead to a disastrous result. I have read that because of its flammability, it is illegal to replace R-12 with R-12a (HC-12a) in the United States. Also, I have heard that once you switch to it, the Hydrocarbon contaminates the A/C system to the point that it can never be completely removed from the system to use something else in the future. 

Hydrocarbons (HC) as in Isobutane (R600a) and Propane (R290) conversions from refrigerants R12 or R134a to R600a is not permitted, as the refrigerators are not approved for operation with flammable refrigerants, and the electrical safety has not been tested according to existing standards either. The same applies to conversions from refrigerants R22, R502 or R134a to R290. Compressors for the flammable refrigerants R600a and R290 are equipped with a yellow warning label and refrigeration systems must be opened with a tube cutter.

If your insurance company determines that the use of R-12a was the cause of a car fire, I'll bet they will not cover it. I strongly suggest researching the product before making the switch.

 
When I asked the questions you have I was told all that had to change was the o-rings to the ones made for the 134. I have changed mine and I was told to get an new canister to go out front since it acts as the filter. The expansion valve on all I have seen is on the outside. I took the entire system apart and cleaned and put new lube in the compressor also. I am actually going to use another type refrigerant called DuraCool out of Canada. They say less pressure and takes a lot less to fill the system also.

 http://www.duracool.com/

I had hoped to get it going this week but electrical bugs have kept me from getting the engine going. This car sat for 26 years.

I cannot say good or bad about the duracool when engine is running I will vac the system and fill and see how it goes.

BTW po had painted all the hoses on my system and I stripped off back to the original hoses and lines so it looks much better.





temporary image upload
Duracool and RedTek are non-approved hydrocarbon based products, also known generically as R-12a or HC-12a. R-12a is completely compatible with the hoses and oils used in R-12 systems. I know a few folks using it in their 80s and 90s cars as a replacement for R12 without having to do any conversion as you would need to do for 134a and they seem happy with it and how well it cools. Sounds like a great alternative and you can buy it on Amazon. 

That said, I am no chemist nor am I an A/C systems expert, but from what I have read I am very leery of R-12a as it is essentially a hydrocarbon and highly combustible, much like Propane. A leak in the system into either your engine or passenger compartment could lead to a disastrous result. I have read that because of its flammability, it is illegal to replace R-12 with R-12a (HC-12a) in the United States. Also, I have heard that once you switch to it, the Hydrocarbon contaminates the A/C system to the point that it can never be completely removed from the system to use something else in the future. 

Hydrocarbons (HC) as in Isobutane (R600a) and Propane (R290) conversions from refrigerants R12 or R134a to R600a is not permitted, as the refrigerators are not approved for operation with flammable refrigerants, and the electrical safety has not been tested according to existing standards either. The same applies to conversions from refrigerants R22, R502 or R134a to R290. Compressors for the flammable refrigerants R600a and R290 are equipped with a yellow warning label and refrigeration systems must be opened with a tube cutter.

If your insurance company determines that the use of R-12a was the cause of a car fire, I'll bet they will not cover it. I strongly suggest researching the product before making the switch.

Thanks for the info. I did read about it before I ordered. I am not afraid of the small amount that is used. I ran a Ford van off Propane for years, 35 gallon tank on the rear of the vehicle and also the 21 gallon gasoline tank, dual fuel. We have the CNG cars and trucks on the road also and big trucks converted to CNG. So hundreds of gallons of fuel there. I do not think a few ounces of flammable gas in the air cond. will be anywhere near as dangerous. BTW the canister for inflating the collapsible spares in our cars has flammable gas in it also.

I am not much of an insurance guy, lol. I do not have insurance on home or 4,000 sq. ft. garage or any of my cars. Would not have on car I drive if not required. That is why they are rich and we are poor making everyone afraid to do anything without insurance. If someone comes on my property to do anything they have to sign a waiver to cover me written by an attorney. Property is also posted so you have to request permission to enter.

The dryer doesn't get here until tomorrow so no progress yet on filling my system.
 
I'm not sure a a/c systen leak could get to the LEL to reach an explosive mixture long enough to be a real hazard.

 
I'm not sure a a/c systen leak could get to the LEL to reach an explosive mixture long enough to be a real hazard.
I don't know if it's possible for a gas leak in the cabin via the evaporator coil to cause anyone to become asphyxiated. Such a leak may be unlikely and there may not be enough gas to have an effect. I just posted the info so we all can make an informed decision for ourselves.

David, I would appreciate an update sometime, as I am very interested to learn from your experience with the conversion to R-12a, aka Duracool. 

Thanks

 
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