Air Conditioning Conversion to R134a from freon on my 69

[70 Charger RT]

Has anyone converted their Charger AC unit so it will work on the new stuff?  What changes are required?  Upgrading compressor?  I'm about to overhaul my heater/AC box and I want to be able to use the new R134a refrigrant.

[Chatt69chgr]

If you want to keep the evaporator and condenser you will have to blow them out to get all the old oil and debris out as well as any metal lines you keep.  Then you will need to buy a new drier with dessicant in it compatible with R134.  Next, hoses will need to be replaced with newer type with lining inside (old hoses don't have the lining and are good for R12 but let R134 leak out).  I think all hoses sold now are of this type.  Change all o-rings to be compatible with newer oil.  Change compressor to Sanden SD508 (will need new engine mounts).  Change expansion valve.  It's pretty involved.  Parts:  try Classic Auto Air in Florida and Old Air Systems in Ft Worth, TX.  Classic auto air should be able to tell you how much R134 to put in.  It's a different amount than when the system was set up for R12.  I don't recall what the new quantity is.  AC systems used the dual type heater core.  Old Air Systems has it as does Classic Auto Air.  Your heater control valve can be rebuilt by a gentleman in California.  His name is Jim ?.  You can google him up pretty easy.  He charges about $125 to do one and does excellent work.

[70 Charger RT]

Thanks for the info.  Looks like I have my work cut out for me

[NHCharger]

While watching powerblock TV on spike I thought on one of the shows they mentioned a new product that was now compatible with the R12 so the conversion was no longer necessary. This was several months ago. Might pay to check out the powerblockTV website and see if this is true.

[Nacho-RT74]

On a Mopar Action magazine I have it says just need to change expansion valve, Dryer ( or its content for a 134 dessicant gel compatible ), O rings. Hoses just if they have been replaced sometime for R12 gas ones, but Original ones will be able to support the 134 gas since they will be enough seasoned to prevent from leaks.

Of course clean completelly the system and replace the oil for 134 one.

On a really professional A/C shop what is the one what makes the OEM A/C devices to assembly lines down here ( including Chrysler ) told me the expansion valve doesn't really need to be changed, since the original one is posible to be adjusted with an allen tool.

No compressor change at all

[471_Magnum]

RV-2 compressors don't work real well with r-134a. The throttling valve isn't calibrated for 134a pressures.

You can remove the valve and install a thermostatic switch on the clutch which will cycle the compressor. Unfortunately, the clutch really isn't designed for that kind of duty cycling, and may wear out prematurely.

Also, the original shaft seal isn't 134a compatible.

134a runs at higher pressure which tends to expose weaknesses in a 35 year old system.

To really do it right, you need to do as Chatt69chgr says.

134a is on it's way out, so there isn't much to be gained by switching.

Price has dropped quite a bit on R-12 in the last few years since the demand has diminished. ~$20/lb last check on eBay.

You can spend $15, take an online exam and get ASE certified to purchase R-12. Just do a quick google search.

[70 Charger RT]

134a is on it's way out

This is the first I've heard of this.  Do you know what they're going to?  Do you know the reasoning for the change?  I presume they aren't going back to R12.

Sorry for all the questions.  I just want to be prepared.

[694spdRT]

I know a guy near me that swears by this stuff in any older system.  Anyone else have any experience with it? I was going to try it in one of my old trucks for kicks next year. He uses the Leakstop and then follows up with the R12a.

http://www.redtek.com/#

[471_Magnum]

There is a drive in the European Union to eliminate R134a. No time table yet. North America probably won't be far behind.

[Todd Wilson]

Theres a new product called HotShot that is compatible with old R12 systems. It works real good and doesnt care about seals and oils.



Todd