I can get the temp down to 46-49 F . I think the problem with the oil is that 134a doesnt mix well with the r12 oil so it doesnt circulate through the system well,which would make for a noisy compressor.The only systems Ive done this on were old so I dont know if they were any noisier than normal.In a perfect world tear it down,get the old oil out and replace it for best results , my old Dodge truck gets the $35 kit from wal mart,my Toyota doesnt have ac

oh what a feeling:
#1 86 xtra cab 22R,EB 261 cam ,Hooker header,2" ex with cherry bomb, Aussie powered
#2 86 sr5 4x4 efi parts truck
#3 87 2wd parts truck
84 supra yard art