How much A/C freon

[woody367]

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

 

[liquify33]

http://www.techchoiceparts.com/refrigerant-and-oil-capacities/chevrolet-light-truck

64oz if I’m reading it right.

ETA: if you vacuum out and refill this may also help:
http://rechargeac.com/how-to/ac-system-pressure-char

As to oil I wouldn’t think so for an orifice tube, IIRC it’s around 3oz oil if you replace the drier (probably should if you don’t know it’s history).

 

[OR VietVet]

You should always replace the Receiver Drier/Accumulator if you open the system. What you do is up to you but you SHOULD. Make sure when you evacuate the system that when it is done and the vacuum is at the lowest it can go, shut it off and watch the needle. If it moves/climbs, you have a leak.

 

[TheAutumnWind]

http://www.techchoiceparts.com/refrigerant-and-oil-capacities/chevrolet-light-truck

64oz if I’m reading it right.

ETA: if you vacuum out and refill this may also help:
http://rechargeac.com/how-to/ac-system-pressure-char

As to oil I wouldn’t think so for an orifice tube, IIRC it’s around 3oz oil if you replace the drier (probably should if you don’t know it’s history).

If the system has a leak the drier needs replaced. Pour the oil out of the accumulater/drier and measure the volume and replace that amount. Replacing orifice tube does not require oil.

My 94 rcsb takes about 2 cans. Fill until your pressures are correct though, dont guess. Get a set of gauges.

 

[woody367]

So I found the decal and if I am reading right ir is 44oz for my Tukon with rear A/C. I will replace the dryer as it has never been changed before. Should I get 3 cans with the dye or just need 1 with dye and 2 without? Also is one brand of refrigerant better then another?

 

[woody367]

With the front and rear a/c is there a separate A/C Accumulator/Drier?

 

[liquify33]

With the front and rear a/c is there a separate A/C Accumulator/Drier?

No.
There is a fan and evaporator over the passenger wheel though.

 

[woody367]

Ok Thank you. Is one brand of freon better the another? Should I use 3 cans with the dye or 1 can with dye and 2 without?

 

[79jasper]

Personally, I wouldn't buy refrigerant that has any mention of "seal conditioner" or stop leak.
If starting from empty, I would just add the dye separately. Add it between vacuuming and charging.


Sent from my SM-N960U using Tapatalk

 

[TheAutumnWind]

Personally, I wouldn't buy refrigerant that has any mention of "seal conditioner" or stop leak.
If starting from empty, I would just add the dye separately. Add it between vacuuming and charging.

Its getting harder and harder to find the ones without stop leak. Ive seen them at walmart and home depot
Sent from my SM-N960U using Tapatalk

 

[imkwuzn]

, 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

 

[woody367]

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.