Hello fellow Aerostar owners. I am the proud owner of a 93 Electric Red, Aerostar XL extended. This is a great site. I bought my 93 new off the lot. The engine has as much power as it did when it was new. I am a mechanic and have taken care of this vehicle its entire life. I have lots of info to share.

I need advice from those of you familiar with swapping the AC system from r12 to r134a. I've looked at all the threads for the last year. I found out about the fx-15 factory compressor being junk after the fact. I purchased a new fx-15 compressor from Auto Zone last week. I now know that Ford superceded the fx-15 with the fs-10. I don't know what year Ford stopped using the fx and started using the fs but the fine folks at Auto Zone show the fx (they have a different P/N) as being the replacement for 93 up to last model year which I believe is 96? I have the 4.0L. Do any of you know where to get a new fs-10 without going to Ford? Auto Zone didn't have a clue about the fs replacing the fx.

I converted my Aerostar AC system to r134 this past weekend. What a disappointment! I didn't do my home work first. Everything went back together fine. Nothing leaked. Vacuum check held 25 in hg for 30 mins. I replaced the compressor, accumulator/dryer, orifice tubes, new o-rings and flushed evaporators, condenser and lines.

High pressure side got too high! Had cool air but no cold air. I now know (after the fact) that a Ford TSB exists for the conversion to r134 that says the condenser must be replaced with a larger one and that air deflectors are required. I'm guessing that the stock fan cannot pull enough air through the condenser and that the condenser cannot cool the high pressure r134 down enough. I believe the TSB introduced a larger fan or an inproved fan clutch. Being that the high side pressure got too high, I was only able to get about 3 lbs of r134 in! I have rear AC and I believe the system holds about 4 lbs. Sprayed cold water through the condenser and the High side pressure dropped drastically

I'm taking it all apart tomorrow, flushing everything thoroughly and find some place to service it up with good old r-12. I know the r-12 is very expensive but the Ford TSB kit will be alot more $$

Do any of you have other suggestions, solutions, or experience with Aerostar AC systems? The factory system lasted 150K.

Thanks in advance and again, what a great site.

Tony T.
96 Mustang Cobra (99K)
96 Taurus SHO (102K)
93 Aerostar XL ext (168K)

 

Tony,
First off, welcome to FTE, always nice to have more contributors with experience.

Your experience closely mirrors my conversion to r134a. Especially spraying the condensor and seeing the pressures drop off quickly. I did an identical conversion as you describe, only at the hose spray point, I decided the problem must be the condensor and replaced it. Same problem. Turned out to be a bad fan clutch was causing the problem. You may want to consider this before shelling out more for a condensor or reverting back to r12.

My conversion works very well without additional air deflectors, etc. It will run at 38 degrees at the center dash vent and slightly colder at the rear unit for some reason. It does take longer to cool down to those temps than the r12 did and is not as efficient during in town driving, but for highway trips, it is more than adequate. After playing around with the system, I concluded that around 55-60 ounces of coolant (5 cans) were required for optimal performance. Too little and too much will both affect the performance of the system. Conventional wisdom at the time, held that one should use r13a at 80% of the amount required for r12, supposedly due to the higher pressures, but I found by trial and error this does not work. The same amount of r134a as r12 (60oz) seems to work just fine. Mine has run for over two years now with no problems. I am still using the old pressure hoses as well.

I bought my compressor from the folks at ackits.com as well as the all the other associated parts and have been delighted with the quality and service.

 

Tony,
I had almost the same experience that Aerocolrado did, with the differences being that I replaced everthing and I got the parts from NAPA and Ford.
Good luck
Fitzworld[

 

I managed to find someone that had hoarded away cans of r-12. The same person also had the r-12 servicing gages/manifold set up. Will be re-converting back to r-12 tomorrow. I will let you guys know how it turns out. By the way, I paid $10 a can!

Also, for any of you that might ever need a technical reference, I own a set of Ford Aerostar/Ranger/Explorer shop manuals.

 

COLD AS ICE! The swap back to r-12 works great! I learned a valuable lesson though. Check your fan clutch if you rebuild your AC system. After I got it serviced up, the high side pressure was still way high and it was not blowing cold. A friend of mind suggested that I try an electric fan. Even the largest electric fan that Auto Zone had didn't work. The electric fan wouldn't even properly cool the coolant temperature. Started to run hot. Took the electric fan back and got a new fan clutch. The old felt like it still had torque. Changed the fan clutch (big pain in the a@#) an that fixed it. Also, sealed the gap between the condenser and the radiator at the bottom. You can hear the and feel the difference of air coming though the shroud.

Total cost, right at $500 for parts.

 

Ok, I know this forum is very old, but here is my experience. R-134a is extremely inadequate in an older R-12 Aerostar. However, RB-276 (Freezone), works better than the original R-12. And the great thing is, you can use it without swapping out the old oils, or changeing hoses, or seals or anything. However, I recommend replaceing seals. I replaced all the hoses too, because a former mechanic overpressureized the system with R-12 and ruined stuff, and I didn't want to take chances. I replaced all O rings, and flushed the entire system. I replaced the accumulater, but not the orfice. I discovered after the fact that I should have replaced the orfice, but it workes very well regardless. I also retrofitted my 1990 Mazda B2600i to RB-276, and it works extremely well. In 95 degree weather, it puts out 35 degree air from the inside vents.

 

One thing that I found (I have converted two aerostars and one 1992 Cougar) is the pressure switch on the low pressure side comes in two flavors. One for 134 and one for freon. The pressure settings are different.
Also, on my last conversion, my 91 Star, I used ESR12, a direct replacement for R134. 42 oz. charged the whole system (it has front and rear air). The manufacturer recommends not to pull a vacuum on the system. Otherwise you might overcharge. The refrigerant does not react with moisture to form corrosive substances. Cools better than the 134 system on my 90. The stuff comes from AUTOREFRIGERANTS, INC. and runs 59.95 for a case of 12 6 oz. cans. Compare that with 134.....I recently paid 15.95 a pound.....

 

I know it is flammable, but so is gasoline, propane works great in r-12 systems. been using it for years.

 

Propane is worse than flammable, IT IS ILLEGAL to use in an air conditioning system. The real risk occurs either if a mechanic works on the vehicle who is not aware that it is filled with propane, or if a leak develops (especially in the evaporator). Not that propane for any given quantity has the capability to be 4 times more explosive than gasoline. Gasoline requires a very sensitive mix to burn efficiently, propane does not, because it naturally atomizes instantly. Furthermore, why use a flammable material, when perfectly good SAFE refrigerants exist?

 

good points, all. but remember all air conditioners are filled with flammable oil that is vaporised in a leak. Many replacement HC class refrigerants are flammable and propane is R-290 as a refrigerant.

Ken

 

After a summer of hell with auto A/C here is what I learned the hard way. If a system, especially in an older car was designed to run on R12 whenever possible use R-12. Any of the blends that are made to be direct replacements for R12 work, however when they leak out they can't be topped off, the system has to be evacuated and recharged. The components that make the blend don't leak out at the same rate, and all A/C systems leak by design. So what you are left with is a mess. 134a is not as cold as Freon in a Freon designed system, too many parts have to be changed to make it really work, and then there is the oil issue.

I have read thru 100's of posts and everyone has a favorite Freon replacement, and many people had no problems with conversions, retro fits, etc. They were lucky, if you want to do the job right use what the system was designed for. Freon is still available and if you do your homework you can find it for a "reasonable" price.

One last point, if the system was open for any length of time change the evaporator dryer, it makes a big difference.

frank1

 

Correction, RB-276 can be topped of if it leaks out. The thing that determines if it can be topped off is if it contains R-22. Any collant that contains R-22 will not leak out evenly, and you will have to completely evacuate and refill. RB-276 does not have this problem. Freeze 12 is similar to Freezone, but it does not contain its own oil. You have to add PAG oil seperately. Freezone contains its own patented synthetic oil that does not react with or damage any parts, and can mix with both R-12 mineral oil and PAG and PEG oils. Before I decided to buy any refrigerant, I researched all refrigerants approved for use in mobile AC systems. You can get this list from the EPA. What is boiled down to was Freezone, because Freezone is the only one that has absolutely no downsides. It is also the only one that includes a one year warranty on the entire AC system, includeing the compressor.

About the above post, regarding flamability, this is not true, as the lubricant used in R-134a systems is a type of glycol, not an oil. Also, all approved refrigerants are tested for flamability, and if any are found to be capable of forming self sustaining flame, they fail approval.

 

I am going to post some information about alternative refrigerants here, so that all of you can be informed and make the best decision.

R-22 will destroy shaft seals on older compressors, usually before 1997. This is a list of some refrigerants that contain R-22:R-406A/GHG/McCool,GHG-X4/Autofrost
Chill-it, Hot Shot (Kar Kool), GHG-HP, GHG-X-5.

The blends using R-22 have another problem, called fractionation, or separation of different refrigerants in the system while the air conditioner is operating. This normally doesn't create a problem unless you get a leak in the system - then one of the refrigerants in the blend will leak out faster than the others. The result is when you try to top the system off, it will not cool. The chemical balance of the blend has changed too much. There are a lot of A/C systems that need topped off a little every year. This means extra expense, time, and trouble for you. The system must be completely recharged!

There is another issue that's even worse. All EPA accepted alternates, including R-134a, must deal with oil compatibility. The refrigerants with R-22 blends must use butane (R-600) or isobutane (R-600a) as an oil carrier. The butane or isobutane carries the oil through the system to lubricate the compressor. Most of the compressors used today do not have an oil sump. They are completely dependent upon oil being carried through the system with the refrigerant to maintain lubrication. So if your oil carrier (butane or isobutane) leaks out, you have lost lubrication to the compressor, resulting in a seized compressor. There is no warranty coverage for lack of lubrication.

R-134a has the same problem as the other alternate blends. R-134a will not carry the R-12 mineral oil through the system. That's why POE or PAG oil is used with R-134a.

The R-134a PAG oil is water soluble! This means the oil will hold moisture unless it has other additives. Water is the
No. 1 enemy of an air conditioning system. It will create acids which attack the metals. The reason this goes unnoticed is because it does not create a problem immediately. The receiver-drier has special material in it called desiccant which traps moisture. If POE or PAG oil is used with the wrong desiccant it will draw the moisture out of the drier and into your system. Eventually the moisture will destroy your A/C system!

There are a number of products on the market that use flammable hydrocarbons (propane, butane, isobutane in many combinations). Here are a few that we know about: OZ-12, HC-12a, Duracool 12a, Enviro-safe, Red Tek, Maxi-Frig, ES-12a and Auto Cool. According the EPA SNAP list, these are illegal to use in mobile A/C systems.

Following is a list of 18 states that have passed a law prohibiting the sale of flammable refrigerants (hydrocarbons or
HC's) for use in mobile air conditioning systems.

Arkansas, Arizona, Connecticut, Florida, Idaho, Iowa, Indiana, Kansas, Louisiana, Maryland, Nebraska, North Dakota,
Oklahoma, Texas, Utah, Virginia, Washington, Wisconsin, District of Columbia

The following refrigerants are EPA accepted, but contain up to 4% butane or isobutane: FRIG-C (FR-12),
R-406A/GHG/McCool, GHG-X4/Autofrost/Chill-it, Hot Shot (Kar Kool), GHG-HP, GHG-X-5.

To confirm this information, call 1-800-296-1996 for the EPA Ozone Protection Hotline.

http://www.epa.gov/ozone/snap/refrig...sts/mvacs.html

http://www.epa.gov/ozone/snap/refrig.../macssubs.html
(look down near tha bottom where it states that the acceptable refrigerants are not flammable as blended.)

If you retrofit to any refrigerant that contains R-22, ou must replace your compressor and hoses to ones that are compatible with R-22. This rules them out as good alternatives.

If you retrofit to R-134a, you must replace the desicant to prevent moisture related problems. Also, all hoses must either have already previously contained R-12, or any new hoses must be approved for use with R-134a (the reason is that R-134a will leak through an R-12 hose that has never had R-12 run through it). R-134a will not work as efficiently as R-12 once did, but may work fine so long as the condensor is sufficiently large, and/or, if enough air flows over it. R-134a may stop working at all if the outside temperature exceeds 95 degrees (this is not true of systems designed to use R-134a, but is very common in R-12 systems that have been retrofitted). Also, R-134 operaes at a higher pressure than R-12 so you may have increased failure rates. R-134a requires that most of the R-12 mineral oil be removed, so the system must be taken apart and flushed. This is because the R-12 and the R-134a oils may react. And since the R-12 oil will not carry in R-134a, it is now a hinderance.

RB-276 (Freezone) contains R-134a, but the other refrigerant it contains lowers the head pressure of RR-134a to the point where it is lower than R-12. This reduces stress on all system components. It contains its own unique synthetis oil, that provides ample lubrication, but in addition, it does not react with other oils, and will carry mineral oil. The R-134a in it will carry PAG oil. The result is that whatever type of system you put it in, you don't have to remove the old oils, and they compliment the system. Freezone does not fractionate, so it can be topped of if some leaks out (repair all leaks). It cools better than R-12 in most applications. It is compatible with most cutoff switches. It is compatible with all desicants. You do not have to add the oil seperately (it is already in the can). As you can see in the above linked EPA sites, it is legal and aproved. It is perfect for use as an R-12 replacement.

Freeze 12 is similar to Freezone, however, it contains no lubricant, and does not carry R-12 mineral oil well, and even then, it requires a higher pressure to carry at all. Useing PAG oil is recommended with Freeze 12, and that requires flushing the old oil out, and changeing the desicant.

 

great A/C write up, now I know what to do when this '96 front rear system leaks for the first time, r134 and still cold as ice on a 100d F day, the condensor in front of the radiator is huge.

 

Hi there I just wrecked my system by putting in 134a and the required oil conversion, my compressor seized broke the belt and left me stranded in the middle of no were. So my question is were can I get that freezone from and what compressor should I use. My van is a 1991 4.0 V6 with rear a/c. Please help I live here in florida and it's over 100f in my van sometimes with the windows open and 60mls.