How much A/C freon

, post: 1456935, member: 30756"]The ac in my 99 4dr Yukon with front and rear ac is not cold. System is very low.My info decal is missing so how much freon should a empty system take, 2.75lbs? I am going to replace the orifice tube the evacuate the system and add some dye. Do I need to add oil if just changing the orifice tube? Thank you[/QUOTE]

My 97 2 door holds exactly 3lbs or 1.36kg without rear AC. I’m surprised a 4 door would hold less than mine if equipped with rear AC?

I just did a complete AC replacement (compressor, orifice, evap/drier). Added new synthetic pag oil to compressor by hand prior to vacuum and recharge. I think it took 8oz total. If you’re only doing orifice tube, I would also recommend replacing the evap/drier as it is cheap and may be contaminated. A couple of oz in the new drier should be fine as most remains in the compressor. If you have access to a professional AC machine, it will measure the amount of oil it sucks out when you initially evacuate the refrigerant before you open the system if you haven’t already done that.


Regards

Ok, so after a month since I first started this post and being sidelined I am going to attempt to get this done. A few more questions as I am a little confused. I bought 4 cans of straight 134a, a orifice filter, a new drier and a can of A/C PRO PAG 46 oil charge 3 oz.

1} the decal on the old drier states 2lbs 122oz for a yukon/tahoe which seems low compaired to what google searcs show. Would this be right? See photo of my earlier post.

2}is the 3oz charge part of the total amount of freon as it is pressurized?

I just want to make sure as not to damaged anything. I was given the oil charge at AUTOZONE instead of just a bottle of oil to pour in. Also should the oil charge go in first or after 1 can iof freon in which is a 12oz can.