atawiz

So decided to do a retrofit on this A/C to R134a. The old compressor started making noise a few years ago and I just unplugged it before it failed. I got a kit from rock auto that came with the compressor, accumulator, orifice tube & expansion valve. Right now I'm in the process of getting what old oil I can out but I have a few questions relating to the new oil. My new compressor says to use the proper oil for the vehicle, my repair manual just says to use the proper oil for the compressor and I get different answers from the autoparts guys. Some say use easter oil & others say use PAG 100 or PAG 150. So I'm stumped. Also, I dont know what amount of oil to use. I know I have to pour "some?" in the compressor. But the label on it don't say how much. I have some PAG 46 & 100 in those little pressurized cans but I think I just need the unpressurized versions.

Also, anyone that's done this did you clean out the old oil? I been told not to by some and definitely do it by others. Since the compressor was on the fritz I think maybe I should. Don't want to do this job again so trying to do it right the first time. Also be replacing the o-rings in the whole system. I've vacuumed it down and it holds for about 5 hours then looses vacuum. Could be my guages but I want to get the new orings on first.

1993 gmc suburban C1500 350 Auto RWD