R-134 in a first gen system.

[rkubicki]

Has anyone out there had good luck converting their R-12 AC system to R-134a? ... . I have seen conversion kits at various parts supply stores (basically adapter fittings, synthetic oil and tap/hose) but have hesitated... . I heard that certain compressor seals in R-12 systems react with the synthetic R-134 oil causing the compressor to fail.



Any responses are appreciated.



-Rob

 

[Dan_69GTX]

The older chrysler compressor, the RV-2, will not work with R-134A. The new compressors - like what should be stock on your truck (a ND brand) should work fine.



Remember - r-134a has a smaller molecualar structure than r-12 so any leaks will be greater after conversion. Any new hoses must be for r-134a (not gass permiable).



There are propper ways and just "ways" to do the conversion. The proper ways is the best - which most people don't do and then they gripe that the r-134a is crap. Done right it will work just as well as r-12 - in most vehicles. Those vehicles that it won't are well documents with professionals.



For the best performance - in a nutshell you must: replace anything that leaks, replace the dryer, knock the orafice tube down one to 2 sizes or replace the expansion valve with one for r-134a, use correct fittings, flush out all components to remove as much mineral oil as possible, fill with correct oil- (pag, ester, etc) remember there are different viscosities of pag oil, use a vacuum pump to remove ALL THE WATER vapor - not just air.



Good luck!

Dan

 

[bvanetten]

And DON'T use PAG oil. It will not let go of moisture, even under a vacuum.



Bruce



Or better yet. Keep all of the r12 components including the mineral oil and charge it with r406a/autofrost.

 

[rkubicki]

Thank you very much!



Bruce, what is the standard application for r406a?... . Where would I be able to get it and do I need a certification to purchase it?



Do you run r406a in your truck's system?



Rob

 

[Dan_69GTX]

Bruce is right - there are many different refrigerants that would/ could/ and do work.



Remember this one little caviot - for a shop to work on your system, they myst have dedicated equipment for each refrigerant they use. That means if you use an "odd ball" that you could have trouble finding someone else to service your system. I'm not saying don't use it - I'm just suggesting that you find out what alterative refridgerants are used by the shops you might frequent.



If a shop has to work on your system and they identify the freon as something other than what they use, it will have to be recovered into a special container and sent away to a special facility that can pull out the different freons and that will cost them/you extra $$.

 

[bvanetten]

rkubicki,



"Bruce, what is the standard application for r406a?... . Where would I be able to get it and do I need a certification to purchase it?"



It is EPA SNAP acceptable for MVAC use and I believe it is approved for HVAC use also. You need to be certified to buy it. It can be bought through many places... here is an example,



http://www.refrigerantsales.com/



Here is some info on the stuff.

http://www.autofrost.com/autofrost-prof.pdf



This is what it is made of,

55% R22, 41% R142b, 4% R600a



"Do you run r406a in your truck's system? "



Soon. My truck is a conversion so I need to get custom hoses made first. I have felt it (r406a) in a oriphus tube system and it blows as cold as advertised. My Suburban will be getting it this summer.



Dan_69GTX is right about getting shops to service your vehicle. I'm assuming your doing your own work and will be maintaining the system. If not maybe you should bite the bullet and put r12 in it or do a "proper" 134a conversion which will probably include replacing the condenser with a bigger/more efficent one. All things being equal, a "proper" 134a conversion might cost more than just keeping r12. Oh, if you change to 134a be sure it doesn't leak in the cab. 134a causes testicular cancer "save the planet, kill the techs" as they say.



Also, if you convert to something other than what was originally in it put a sticker on your core support identifying the type and amount of referigerant used.



Good luck and do your homework.



Bruce

 

[Dan_69GTX]

Good point about the sticker - I forgot to mention that!



R-134a causes testicular cancer - fun - didn't realize that. Of course I still use the old propane torch adaptor to find r-12 leaks - NOT. (for those unaware - r-12 and flame = toxic gases)



Dan

 

[bvanetten]

Originally posted by Dan_69GTX

I still use the old propane torch adaptor to find r-12 leaks - NOT. (for those unaware - r-12 and flame = toxic gases)



Dan

Aah! Isn't the automotive AC business lovely!

 

[rkubicki]

I was planning on doing the work myself but I don't have a certification... Looks like my only option (short of taking it to an AC shop) would be to do the 134a conversion... . If I had to take it to a shop I think I would just let them recharge it with R-12.



Otherwise, I will definitely do a thorough leak check before charging the system with 134 - I like a cool cab in the summer but not at the expense of my two best friends



You guys are great... . Thanks!



Rob

 

[moparguy]

What about 276R

Got a friend that's a commerical ref. tech, he's trying to get me to run 276R, said it works over R12 and cools fine on it's own.



I've cruised some of the alternative AC sites, and haven't seen it mentioned.



Anyone know anything about it.



Thanks, Ronnie

 

[bvanetten]

What's this 276r stuff? I've looked for 276r and r276, found nothing on it. None of the MVAC of HVAC sites have anything on it.



Bruce

 

[Dan_69GTX]

I have a 2. 76 8 3/4" pumpkin - but I don't think it would fit in the A/C.



In otherwords - nope - I have no clue.



Hey Bruce -



What refridgerant oil do you generally use in Dodge trucks - say a 96?? I know they call for PAG, but have you ever converted them to use Ester?? Plus I've never found out what viscosity is recommended in them - what do you use?



Do you do a/c stuff for a living, on the side or ??



I used to do it, but now just keep my own stuff going and do a little work on the side. I stocked up on r-12 when the price started going up around 91 - glad I did.

Dan

 

[wraney]

I dont want to step on anyones toes with this,but last summer my ac (91 dodge) was low on freon and the parts store suggested freeze 12 ??? so I added 1. 5lbs to my system of r12 without any problems,so far. Has anyone else tried/heard of the freeze 12. Cost about $3. 00??? a can no certification required. Starting to use ac more since it's summer and still gets cold gonna check w/gauges but may need half a can or so.

 

[Dan_69GTX]

Ouch - Stop stepping on my toes - My 5 year old does that enough!



Freeze 12 seems to be common in Texas area. I'm not sure where Dumas is, but when I lived near Tyler (80 miles East of Dallas), that was a common solution. Yes, it seemed to work well, but you have all the cautions and warnings of the above posts. If you still don't need to be certified to buy it - GREAT. But a shop that uses it must still have dedicated equipment for it (according to EPA) - that is several grand in equipment to use that.



Dan

 

[JHolt]

R-134 in the veins

I had mine converted to R-134a last year, at a shop where they purged the system and checked for leaks. No compressor problems so far... Of course, a few months later it all leaked out (under the hood). It was a bad expansion valve and would have been under warranty had I not supplied the part myself. It doesn't get cold real fast, but after a while it cranks the cold pretty well. However, it never worked all that great before I swapped all this into the crew cab (was running R-12 back then), and I even had it completely gone through including a new evaporator before the big crashbangsmash. But it does the job, I think it would help if it had a better blower motor. Especially with the crew cab now, it could use some more gusto to get the air to the back seat area. Anybody found a better replacement blower motor?

 

[jimk]

freeze 12

I have used freeze 12 in some dozers for a few years now now . I dont wont to get into any legal or other bad things so I will say I think that freeze 12 is 134a and 152b a blend. Dont use the sight glass in the dryer to charge or you can get to much of the freeze12. I have charged the systems to where the suction going to the compressor was getting cold and stoped. What you dont wont to do is get liquid on top of the pistons.

I have heard of the gass in some blends that broke down and caused all kinds of problems.

All I can tell you is that the air is cold, maby not as much a 12 but good enough. lol Jimk