do i have R-134a?

[jgilbs]

i have a 92 x and i was doing some prelim research under my hood to see what i might need to replace when i upgrade my R-12 system to R-134a.
i looked at the sticker on the evaporator core and it was the factory sticker that said the system is R-12. but upon closer inspection of my A/C system, i noticed three puzzling things. 1) new compressor(or rebuilt - it had the Ford factory reconditioned seal on it and it looks newer than the rest of the engine components - that is to say, there is less rust.) - this is not puzzling in and of itself, but consider the other 2 things. 2) My hoses leading from the compressor to the accumulator/dryer say "R-134a" 3)The schraeder valve on the accumulator/dryer has a green o-ring, and i thought green o-rings meant that it is an R-134a fitting. i dont have a digicam to take pics, but can i be pretty sure that the system was upgraded prior to me buying the truck (i got it used in October of 2002.)? is there any way to test the system to confirm it is in fact R-134a? when i removed the schraeder valve on the accumulator, it started hissing, indicating that there is still a residual charge of freon. how can i tell for sure what kind it is? i dont want to go and buy the wrong type of freon and destroy my otherwise good compressor.

EDIT: The schraeder valve to the condensor also has a green o-ring. also, where would they put the sticker stating it is R-134a? i have heard some places put it on the radiator. i replaced the radiator in january and i cant remember if there was a sticker there. does anyone that has a "legal" conversion have the sticker on the radiator?

 

[wpurple]

If the system was upgraded by a "legal" shop, then they are required to place a sticker stating that it has been converted and how much R134 was added.

If I were to guess I would say that it has been converted based upon the fact that R12 is hard to come by and very expensive.

If the system is not working, it may just need some R134. The old system if not converted correctly, will leak the R134 as the molecules are smaller than that of R12 and pressures are higher.

Less than overhauling the system, start out with about 1/2 lb of freon, see if the compressor kicks in. The total system doesn't hold much more than a lb anyway.

Good Luck.

 

[jgilbs]

has anyone ever tried that R-134a "leak stop"? how did it work for you? if i do have a leak, i would imagine that it would be very slight, seeing as how the system still has pressure and i know for a fact no freon has been added for 1.5 years, so the freon with "leak stop" in it might be the ticket.

 

[wpurple]

Certainly wouldn't hurt, again, I bet it's a "natural" slow leak of the R134 out of a R12 system.
If it comes down to adding freon here and there to keep it going, it would be cheaper than a overhaul.

BTW, when adding Freon, put the can of freon in a bowl of hot water, that will speed up the process of adding it.

 

[jimbo74]

freon is r-12 not r134a

 

[jgilbs]

actually i believe "freon" is the generic term applied to all types of refrigerents, including r-12, r404 and r134a. kind of like u can "xerox" something on a machine made by canon.

 

[Robb]

If you happen to be the type of person that is EXTREMELY **** about such things............yes, freon is R12 and R12 only.

In common lingo though, the term "freon" is thrown around to describe multiple refrigerants.

 

[jimbo74]

like channel locks is an actual brand name bit most people dont call them slip joint pliers....

 

[jgilbs]

ok, so apparently it is still R-12 - I got a gauge for R-134 fittings and it didnt fit. whoever had the truck before me must've had some major service done on the A/C system, since all the hoses say R-134a and its a remanufactured compressor. wonder why he didnt just convert the system at the same time? oh well, looks like ive got some work ahead of me

 

[Glacier991]

A good AC shop can hook up a tester and tell you the type of the refrigerant and the purity. I'd start there, since you cannot buy R-12 yourself anyway.

 

[wpurple]

http://inventors.about.com/library/inventors/blfreon.htm