FrostByte

Im a refrigeration tech but dont do much on cars.

1. If your car was converted to 134A then there should be stickers (cant misss em) stating so.

2 & 3. You conneced to the high or liquid line. The "high side" pressure will be high enough to pin the needlw w/ that kit u are useing if the engine is running & A/c on, even if you are low on refrigerant. The clutch is engaging and disengaging every three seconds or so. Thats called "short cycling" & is caused by lack of refrigerant.

If your car hasnt been converted for 134A I wouldnt add it. 134A isnt compatible w/ mineral oil & thats what is in your system now. Its like oil & water, the refrigerant & oil dont mix well. The oil dosnt return from the evaperator & your compressor seizes. 134A is ONLY compatible w/ Poly-ester oil. "Hot Shot" R-411B will work w/o retrofit of hoses & other parts , but you cant buy it unless you are EPA certified. http://www.icorinternational.com/hotshot_opening.html You should take your car to a CERTIFIED automotive A/C mechanic to find & repair leak. Dont take it to a dealer, they wil rape ya & only retrofit, not repair. Go to a garage that dosnt do A/C themselves & ask who they use or recommend. The system needs to be evauated w/ a vacume pump to remove contaminats such as air & moisture.

If you are able to connect connect that kit to either fitting then is a kit for retrofitted cars. When they went to 134A the "idiot proofed" the fittings so u cant connect incorrectly.

FiveLiterRiceEater

i have 2 problems with that last post, the biggest one being the slam on dealers. sure, they may rape you, but that doesnt mean they're not going to fix the problem. everytime i do a retro fit we hold a vacuum on the system to find leaks, and when we find one we fix it. and 134 is compatible with all oils. PAG, mineral, and ester. r12 and pag, however will create an acid. other than that i completly agree.

Twisted

Thanks for the replies everyone. And thanks Frostbyte for the great info. So I just went outside, and started the car, turned the A/C on, and connected the can of R134. The guage read a lot lower than it did before. It fluctuated from the top of the green (charged) section to the bottom of the green section, in accordance with the cycling of the compressor. Now, the main question is: Can I be sure that my system has been converted to R134 just because the R134 can fits on the fitting on the compressor? Frostbyte, I know you said that there should be a sticker somewhere in the engine bay. I looked, but could not find one. So I did not actually spray any of the liquid from the can into the system. I'm still unsure whether the system has been converted. What do you folks think?

Also, Frostbite said that the fitting on the right is the high-side fitting (at least I think that's what he said), whereas others says that it's the low-side fitting. Now I'm confused.

FrostByte

Dealers are going to retrofit ONLY. You can find a garage that will reapair w/ hot shot

My friend, i have been doing refrigeration for 20 years now. I have worked for a walk-in cooler mfg as customer support & preseantly do warranty work for 3 manufacturers of refrigeration equipment, TRUE MFG, MANITOWOC ICE & SCOTTSMAN ICE. I have designed refrigeration systems for major food manufatures & distributors.

The oils will not create acids. Acids come from moisture & refrigerant w/ heat as a catalyst or by an electrical failure.

FiveLiterRiceEater

the line going into the condenser, which is infront of the radiator is the high side line. its high pressure from the compressor. the other line is the low side line. it feeds the compressor low pressure vapors. I looked at my mustang, and i have 2 tire valve looking fittings, and i know mine is an r12 system. im gonna guess that if yours has a 134 fitting, then its got 134 in it.

FiveLiterRiceEater

thats all good and fine, but i work at a gm dealer that does more than just retrofits. and if they dont create acids what will it do? just break the oil down?

Twisted

OK so, Fiveliter and Frostbyte, you both agree that if there is an R134 fitting on the low-side, then it should be an R134 system? Just want to clarify. Don't worry, I won't hold either of you responsible if I mess my car up.

Now comes the matter of the system needing to be evacuated, as indicated by Frostbyte. So I shouldn't just fill the system with the can I bought (assuming my system has been converted)?

Twisted

By the way, thanks for verifying that my fitting isn't the factory fitting.

By the way, I'm tempted to just throw caution to the wind, and fill the damn thing. I figure, if it is an R12 system, I'm probably never going to fill it anyway.

FrostByte

dont believe me?---------> http://autorepair.about.com/cs/gener...a060301a_4.htm

FiveLiterRiceEater

no. you'll want to evac the system to make sure any comtaminated refrigerant is out. and have a vacuum put on it for 5 minutes to make sure it doesnt leak. then you can fill it to 75-85 percent of the r12 capacity, but fill it with 134a. you only go with 75-85% because 134a will have a higher pressure at a given temp than r12 will. and you can also have them put some dye in the system. this way, you'll have the correct amount, know if there are leaks, and will be able to detect leaks if they come up in the future.