Gentlemen,

The A/C on my 94 Seville (163k miles) kicks off because the freon is low. The local Autozone sells everything I need to charge the system, but they can't tell me which oil(s) I need. I know she takes the 134a freon, but don't know about the oil.

Can anyone tell me which oil she takes? Does she take only the oil that gets added into the lines? Only the kind that you pour into the compressor? Both?

This will be the first time that I've ever attempted to charge an A/C of any kind; so information about something that's not obvious would be appreciated.

Thanks, Jeff

I've learned that it's best to get your system recharged with the correct guages. Your car holds more than 2 cans of 134A but less than 3 cans so it may do you good to buy the guages too if you don't already have them.

I'm not sure about adding new oil if you're only refilling the system.

Well adding ESTER oil is what u do when u replace your compressor. Adding the oil they have in the can by the refigerant is if you system is completely drained, if u have pressure at all, u probrably wont need any oil.

I would put a little oil in if you have very low pressure, just by pushing in the valve like a tire, other wise just do as recommended. If you dont want to buy the gauges, just do like instructions and leave the can right side up as u would your last can u put in. This method gets very close to recommended readings, i had someone hook up gauges after i did mine and he said he wouldnt change a thing.

Oh, they make a tire gauge style meter for like $5 at any auto parts store

Thanks for the replies.

I don't know how low the pressure is because I don't have any gauges currently. I'll grab the gauges and a couple of cans of 134a. It sounds like ya'll aren't sure about the oil as we don't know what my pressure is down to. All I know is that the instrument panel tells me that it's so low that it's shutting the compressor clutch off. I'll try and get out at lunch tomorrow and grab the gauge cl1986 is talking about and post my pressure.

Perhaps someone knows at what pressure threshold I should also add oil?

Thanks, Jeff

Don't add any oil unless there was a sudden and catostrophic loss of refrigerant.

I've bought a couple of cans of R134a and a nozzle with a pressure guage from Autozone. Perhaps you guys could verify for me that I'm about to hook up to the correct nozzle on my 94 Seville's cooling system. Seeing all the warnings and promises of death and dismemberment if I hook up to the pressure side, and considering that this is my first time charging an A/C and that I don't quite know what I'm doing, I'm a little (over) cautious.

I have identified the suction nozzle to be the one on the passenger side embedded in the engine coolant reservoir. Is that correct?

Also, as the instrument panel says that my compressor is off because the refrigerant is too low, will the R134a pump into the system with the compressor off? If not, how do I get her to kick on?

Thanks, Jeff

No, it will not take refrigerant til you clear the code through the DIC or pull battery power. Have the can hooked up (inverted so as to fill as a liquid) and ready to go when you turn on the A/C so it will draw in refrigerant before it trips the low pressure sensor again.

You have the correct service port identified but don't worry, they made it idiot proof. The high pressure side is a larger nozzle so you can't hook up to it even if you try.

Success...

I cleared the codes, started her up with the A/C off, hooked up the hose and refrigerant, opened the valve to let the refrigerant flow, turned the A/C on and to 60 degrees and stood and watched the compressor cycle on and off while she sucked in the R134a. The first can brought the pressure up to 40+lbs and the second brought her up to 50.

It's 94 in Dallas right now, but it's only 78 in my Seville.

Thanks, Jeff