What steps do I need to take to convert my R12 to 134a? Or does anyone know of a good website with step by step instructions? I have an '88 Ford Bronco II 2.9L, 2wd. Thanks for your time & help!

 

First have any remaining R12 reclaimed. You will need special release tools for the quick disconnect fittings. Here is a list of new parts. Compressor, high side pressure line (which has orfice tube built in). This is the small diameter line that goes from the condenser to the evaparator,new accumulater,new R134a o-rings for all fittings taken apart,high and low side conversion fittings for service ports,8ozs R134a PAG (not ESTER) oil from Ford, add on filter (installed in the high side line between the condenser and the line),3# R134a. Start by removing compressor. Pour 2ozs of oil in suction port of new compressor and install. R and R high side line with add on filter (new compressors warrantys will be void if this step is not done). R and R accumulator (add remaining 6ozs of oil to accumulator).If this is not possible add oil later with your recharging station. Remove old valve cores from service ports and install new R134 fittings. You should now be back together and ready to hook up to vacuum pump for a minimum of 1 hr. Rotate clutch plate on compressor by hand about 12 times to destribute oil that you poured in. That done, charge with R134a. R134a takes up more room than R12 so you will not put in as much as the system originally held. Rule of thumb is 80%. Example if the system originally held 2# 12ozs R12 Install 2# 4ozs R134a to start. You can bump it up a little more if necessary. You might have noticed that I did not say anything about flushing the system to remove debris. Cutting open comdensors that have been flushed show very little debris ever really got flushed out. Thats what the add on filter is for. You may even have to change this filter after system has run for awhile. One final varable. Some Ford compressors that go bad create a problem known as (BLACK DEATH), dark deposits on the inside of the lines. If you find this condition it is recommended that the condensor be replaced also. Good luck.

 

Thank you so much for your advice. Helped immensely!!!
Holly

 

I was wondering if you succeded. Glad I could help.

 

 

JUST GO TO BTT.ORG. CLICK ON THE LINK TO ENVIROSAFE. IT WORKS GREAT, AND NO VACUUM PUMP REQUIRED.

 

Sir, Envirosafe is a hydrocarbon (isobutane) blend and is illegal to use in any mobile AC system in the US. If the OP is in Canada, it's a different story, but disclaimers apply about proper system preparation for HC refrigerants, and the work must be done by a certified shop. The part about "no vacuum pump needed" is pure, unadultrated, scam artist, wallet flushing bull**** when servicing any AC system.

 

Wow, I wish I had the patience to type all of that out. Really good stuff.

I would take exception to only 4 details (The rest was right on the money):

Condenser flushing. R-12 serpentine Condensers historically flush well, Unless you're talking about a "Black Death" failure. Then condenser replacement is recommended. In normal compressor failure cases flushing is preferred and filters arent needed. Black Death failures currently require "firewall foreward" replacement of all components. R134a parallel flow and picollo type condensers should always be replaced when a compressor "grenades". Their design doesn't lend itself to sucessful flushing.

Compressor. If the compressor is good and not leaking, it doesn't need to be replaced for conversion. (Ford FX-15 "Black Death" compressors should always be replaced with a different type unit before conversion).

PAG oil. PAG should not generally be used on conversions due to problems with it combining with remaining R-12 molecules and forming acids. If all of the rubber has been replaced, the system flushed, and compressor replaced (Blck Death failure repair?) PAG is fine for converted systems. Newer "Double End Capped" PAG oils are proving to be good in converted systems without problems. Ester should be used in any converted system unless it had been totally rebuilt with all new rubber. DEC PAG oil is showing real promise in converted systems that are converted "properly".

Inline filters have much become a thing of the past for converted systems. They were recommended, with some success, for repairs on systems that had "Black Death". It has since been determined that a "firewall foreward" replacement is the best way to fix a Black Death system, the filters wren't sufficient. On an R134a system with a "non-Black Death failure" flushing and condenser replacement is recommeneded due to design.

 

You know the more I research these replacement products the more I believe they are all scams. I was talking with some guys at the local parts houses. Here in this part of Arizona where temps reach 132 degrees in the summer. The general opinions are there is R134A & R12. That Freeze 12 was a big deal here when it came out then mechanics that were working with it started getting sick. Even Checkers here is getting rid of all these substitutes. And going with ONLY R134A. There is a parts house here that if you are licensed you can buy R12. What I can tell you about Envirosafe is I believe it helped shorten the compressor life on my Ford. I was talking with lsrx101 on PM. The other day I found the problem with my Ford on R12 is the compressor. I had forgot but a couple of years ago I was low on charge and a friend of mine said try some of this. IT WAS ENVIROSAFE. Now I have a compressor going south. I can't prove it was EnviroSafe but that compressor was NEW in 1999 and was find until I added Envirosafe to an R12 System. Ever since it hasn't worked as good. So I converted my wife's 88 Dodge D250 to R134A, I will now have to replace a Compressor, Filter/Dryer, pull a vacuum and charge with R-12. The reason I don't convert it is because I have Factory oil & tranny coolers that block the condenser. There is no place to move them. So Several A/C guys tell me to stay with the R12. I'm a licensed tech. Most of my experience is with high pressure commercial refrigeration. I have worked with auto A/C and have an ASE cert. But I have to listen to the A/C guys that work with autos all the time. Just like when their building A/C goes down they call me.

 

Great points kermydog. Yep, those "drop in replacements" can cause all sorts of problems. They can be made to work well, but the manufacturers don't tell you how to use them correctly. They like to give the impression that all you need to do is "use this product and your AC will work better that ever". Their lack of proer instructions usually does nothing but make them (and me) money. Sorry you got burned by a helpful friends ignorance. (I mean lack of knowledge, not stupidity).

Hey kermydog, Next time you have a commercial AC go down, can I come over and fill it with strange refrigerants, boosters, sealers, and other "magic in a can". ? It seemed to work so well in your truck