Adding ester oil to the compressor?
 

I had a condenser leak (replaced it) so I need to pull a vacuum and add R134 again.

So I don't burn up my compressor what are the correct steps for adding ester oil? (I have a Nippondenso compressor)

Pull a vacuum then add the esther oil via the low side? Do I start the motor or will the vacuum just pull in the oil?

or

Do none of the above and add the oil to a fill port? pior to pulling vaccum?

You need an oil injector. Looks like a syringe or small caulk gun. That way you do not have to recharge. Or you can buy a can of oil pressurized with R134. Goto tooltopia.com. They have lots of A/C tools. Joel

Wait, if you are not pressurized, just add oil into the vac side line. If you have the compressor off you can pour the oil it has left out. That way you can get an idea of how much oil you have. Joel

If all you removed was the leaking condensor you didn't lose much oil so be carefull adding too much. In my opinion you should only add 1 to 2 ounces, if you add too much the system could hydraulic lock. Are you sure Ester oil is what is in there now?

Not sure if it's PAG or POE-not specified on the invoice from the shop. Would I have to flush the whole system since I have a 50/50 chance of two different oils?

I went with ester as it it recommended on this board.

Should I just drain it and put in fresh since I don't know how much is in the compressor right now?

Man this a/c repair seems like it never going to end. Just when you think you are almost done somethings else occurs.

It's not that easy to drain the oil. Keep in mind you have about 50 feet of rubber hose,the evaporator,the receiver drier,compressor and probably a front condensor that all contain the oil. To do it right all would have to be drained/flushed and now you have to worry about the expansion valve. Can you call the shop you refer to in your post and find out what oil they used?

I did call the shop and they said, "we used whatever oil came with the conversion kit."

Of course they never bothered to post a conversion label or even change the o-rings to R134 compatible.

I'm just going to go with ester. This a/c fix has consumed my life for two weeks and I'm done.

Tomorrow I'm pulling a vacuum and recharging.

Thank you to everyone for their help.