[89stanger1989]

i was just curious because i replaced my compressor and everyone is telling me i need to vacuum the system which i will do but how do the other people just add freon without vacuuming the system and it still works fine...when do you need to vacuum it and when don't you need to vacuum it?? also how do you oil the compressor? can you do that while its in the car? please help me before the sun comes out ..thanks

[mustanginky]

if your car is r134 the refrigerant is the lubricant. if it's r12, i don't think it lubricates as well.

as far as vacuuming is concerned, your system is a sealed system. if you don't vacuum, you wont totally fill with freon, there will still be air in there. vacuuming is what you would do to allow it to fill up completely. i don't think you'll get much freon in there without vacuuming. plus, it removes moisture from the system, which you dont want.

keep in mind, this is what i learned in HVAC 10 years ago in highschool, so if i'm not 100% right feel free to correct me and sorry if i give bad info.