replacing ac compressor.

[dav-02ws6-m6]

Ok I was wondering what are the steps on replacing one. The ac compressor went bad on my brother's duramax. One of my questions is once you replace the compressor and install all the o rings and connect the lines, are you suppose to hook up something to get the air out of the system or do you just add Freon?

Thanks for the input.

[2002ssslp]

Before you put in the oil and 134a you need to evacuate the entire system with a special vacuum pump.

[dav-02ws6-m6]

Would I still have to add oil if it is a used compressor. And would one of those vacuum pumps used for a home air conditioner work on a car.

[2002ssslp]

Yes and Yes. you still need to add oil to the system. I would put the used compressor on the car. run it and evacuate the system and then out in my oil and 134a.

[JayTA98]

I just did my compressor in my TA about 6 months ago. If you get a new compressor you need to read the package some compressors come with oil already in it and you don't need to add much oil or any at all. Also you need to flush the lines to clean all the gunk and particles in the lines. Clean the in line(orifice valve) valve or replace. I always get a new dryer and i try to flush the condenser real good until it comes out clean. Install new o rings on all the fittings, the whole kit cost around $10. Once you do all the cleaning and reinstall everything then you need a vaccum pump to vaccum the system. Add oil if you need to add more according to the specifications. Add the correct amount of R134.

Do not add more oil than needed. I didn't read my compressor package and it was prefilled with oil. I added 5 more ounces on top of that. The system will not cool efficiently. I asked a good mechanic of mine and he told me I could be a bad evaporator(which is inside the dash). A pain to remove. I then found the package and read it. I asked multiple mechanics and A/C techs and they all told me the same; too much oil will cause cooling problems. I stored the R134 (again) and took everything apart. I flush everything including the evaporator(except the dryer you don't flush it). I didn't flush the compressor or drained the oil (since it had oil in it). I put everything back together, vaccum the system, add R134 and it works like a champ since then.

[dav-02ws6-m6]

Sorry for answering very late Its just that I haven't had time to get to it. I'll be using a used compressor how can I tell if it needs any oil? I also notice that at the auto parts they sell little cans with oil, are they any good?