AC questions for the experts

-
MoparMike1974

MoparMike1974

FABO Gold Member
FABO Gold Member
Joined
Jun 16, 2017
Messages
4,573
Reaction score
4,372
Location
Maryland
I have a few questions regarding AC. I went to buy a 30lb 134A and found out you now need to have an EPA 609 cert to buy, at least in MD....probably all states? Anyways, just curious how hard the test is and what kind of questions to expect. The test is open book and no time limit but the "manual (online)" is massive. I plan on buying 3-4 jugs of 134 to hoard for when they ban it eventually.
Next questions are about the factory AC in my 71 swinger. It still has some gas in the system so im thinking it will work with a recharge. So to change over to 134 I would be looking at a complete flush, new drier, new expansion valve and oil. I am aware that the 134 wont like these old hoses but if I have to top the system off here and there that is fine. Am I forgetting anything here?
Last question is just an odd thought I had. I have a new sealed 30lb of R22. Can this be used in the R12 system? If so is the conversion process the same? Any benefit over the R134?
 
I have done many many conversions sense the early 90's and in 2000 they said just drain it put in some PAG oil and charge it up nothing else needs to be done. My buddy's car that I did in 2003 or 4 is still working great today.
 
Can't use R22 in cars the pressures are way different.
 
I remember them selling the retrofit kits and all they had was the fittings and a container of pag oil. Now I read that the expansion valves are different for 134, etc etc.
I know the oil is not compatible, the old ester oil wont suspend in the 134 or something like that.
Im still curious to know if the R22 will work in this. Although I might be better off selling it. They cost around $500 for a 30lb cylinder.
 
My 93 was maybe the last R-12 system year but the R134 conversion was a screw on valve, sticker and a bottle of PAG. It Worked. Last time I bought some R12 from someone legit, I just had to sign a waiver saying I would not resell it. R1234xyz is the new Euro stuff and its friggin liquid gold, or so they seem to price it as.
 
Ok, so the 22 is out of the equation. I know a guy who does home AC work, will see if he is interested in it.
 
I priced 134A at advanced auto under our commercial account. I can get it for $100 per 30lb. Reasonable enough.
 
I've seen professional shops put 134 right on top of 12 all the time with no ill effects. I'm not sayin it's right or recommending it. Just saying what I've seen.
 
Im going to order a new drier, flush the system, pull a vac and throw in some 134 and see what happens.
Just got the car this weekend. Was supposed to be running recently but he said the fuel pump went bad. Im going to try getting it running by the weekend and then the experiment can begin.
 
R-12 and R-134A are "low temp" refrigerants. R-22 is a "medium temp" refrigerant. You have to understand that a refrigeration system is designed to operate around the characheristics of a given refrigerant, boiling point specifically.

As far as the test required for the purchase of refrigerants to help satisfy the Montreal Protocol, anyone can likely pass it if you have a rudimentary knowledge of refrigeration and air conditioning. The test involves your knowledge on container handling, legal issues with recovery and disposal of the refrigerants, as well as storage and recordkeeping. They tell you everything you need to know just before you take the test, and it's not really about working on anything other than prevention of loss. There are multiple sections to the test so that people can pass and be legal for their given field, yet maybe not be legal for stuff they dont mess with, i.e. Ammonia.
 
Last edited:
MoparMike1974 said:
I have a few questions regarding AC. I went to buy a 30lb 134A and found out you now need to have an EPA 609 cert to buy, at least in MD....probably all states? Anyways, just curious how hard the test is and what kind of questions to expect. The test is open book and no time limit but the "manual (online)" is massive. I plan on buying 3-4 jugs of 134 to hoard for when they ban it eventually.
Next questions are about the factory AC in my 71 swinger. It still has some gas in the system so im thinking it will work with a recharge. So to change over to 134 I would be looking at a complete flush, new drier, new expansion valve and oil. I am aware that the 134 wont like these old hoses but if I have to top the system off here and there that is fine. Am I forgetting anything here?
Last question is just an odd thought I had. I have a new sealed 30lb of R22. Can this be used in the R12 system? If so is the conversion process the same? Any benefit over the R134?
Click to expand...
Here's a dirty little secret. The gas in those computer duster cans is actually 134a. My son tried this on his old Toyota that used R12. Still works.
 
I found an old can of that office computer duster and it was R12 !! Said it right on the label.
I know I saved it but have no idea where its at now.
 
I saved the can because I had never had imagined they would use R12 in something like that. Can looked like it was from the 60's. It had a little left in it so I used it. I remember now, it was freeze spray for freezing IC chips to isolate heat issues.
 
You can but R134a off Amazon in the small cans or 30lb size pretty cheap with no hassle
 
Lefty71 said:
Up, up and away through the hole in the ozone layer. :eek:
Click to expand...
Don't drink the Kool-Aid. DuPont owned the right to "FREON' R-12. Then the ozone scare. But low and behold DuPont comes up with the environmentally safe R-134A. Difference? R-12 sold for 19 -49 cents a can, The new and improved R-134A sold for like 15.00 can when it came out. Hummmmm? They then came out and said, one volcanic eruption did more damage to our Ozone than a 1000 pounds of R-12 being released every day for a 1000 years!
 
EPA 609 is pretty easy to get. I have 608 Universal and don't mess with auto AC outside of my own cars. You can download study material and schedule testing through www.escogroup.org.

You might find some useful info at this link. Its a corvette R134A retrofit but the same principles ought to apply:
Updating Air Conditioning from R12 to R134a – The Corvette Restoration Page

I think the R134A won't be compatible with the seals in your R12 system, so you'll probably see leaks. R134A is still pretty cheap so it'll get you by until you can do a proper conversion. As far as using R22, it operates at different pressures. I wouldn't try it myself. In commercial and industrial work R22 and R12 are not considered equivalent and one is never substituted for the other (even after a system rebuild) because the operating pressures are so different.
 
Yes I fully expect it to leak down, mainly due to the type of hoses. The new hoses are basically a hose inside a hose. I would be fine with having to top it off once or twice a summer.
 
Put a salvaged factory air in my 69 cuda. Used original everything including hoses. Changed the drier and expansion valve because it had been sitting open a long time. put pag oil in compressor. On my second summer now, no leaks. All the seal, hose, and Oring replacement talk is a bunch of hooey.

Buy a $20 leak detector at Amazon. Find any leaks and fix and you are good to go.
 
I ordered a new drier for it already. Just bought a leak detector, should have bought one years ago.
 
Mike69cuda said:
Put a salvaged factory air in my 69 cuda. Used original everything including hoses. Changed the drier and expansion valve because it had been sitting open a long time. put pag oil in compressor. On my second summer now, no leaks. All the seal, hose, and Oring replacement talk is a bunch of hooey.

Buy a $20 leak detector at Amazon. Find any leaks and fix and you are good to go.
Click to expand...
Same here. I kept all the original hoses, expansion valve,drier I did replace. On my 69 Dart, been holding pressure for well over 6 years now on R-134A.
 
You must log in or register to reply here.
-

Back
Top