A/C broke...re-visited!

[Steve Waddington]

Its been almost two years< and I had posted a thread about getting my smog done on my '03 Tahoe LT, when the a/c quit!
Since then, thanks to all the help here, I replaced the likely culprits in the smog chain, put a few miles on it, and it passed smog just fine! So thanks for that!

Now...I still haven't fixed my a/c...and here's what I said at the time:
"...while waiting in line for over an hour with truck running and a/c on...all of a sudden there was a loud whine from under the hood! (almost like the sound of a horn with a very weak battery)
The smog guy said... “ turn off your a/c”. I did and the noise went away. Turned the a/c on again... and bad noise returned! Shit!"

Still makes that terrible noise if I turn on the a/c. No noise if the a/c is off. And the ac blows warm. Before the incident, the a/c worked beautifully, front and rear.

So...Just like I did when fixing the smog issues...I guess I'm just going to replace whatever might be wrong... the entire compressor...and I think there are a couple of other things to replace too..orofice tube, dryer, tensioner pulley, belt?
But I read where I have to purge the system first? Can I just take it to an a/c shop and tell them I'm gonna replace everything and have them purge my system...and after I install all the stuff...charge it back up? Will they even do that? Is there anything else I need to do?

And anyone have any ideas of what parts to get? There are so many listed online...and the prices vary by hundreds! I don't want cheap crap...but I don't want to overpay either! And I do have rear a/c. Does that make a difference in parts?

Thanks.

 

[Scottydoggs]

clutch on the compressor, or the compressor its self took a dump on ya.

 

[rockola1971]

You can have a shop purge your system then you are free to replace everything (compressor, orifice tube, all orings in system, drier and wouldnt hurt to flush out system either) but if you dont get it put back together air tight the shop that has to vac it down and charge it is going to either tell you it isnt sealed right (vac will tell if system is sealed or not) and give you an estimate to redo your oring work or just do it and charge you for it. I recommend having a friend that knows what they are doing help you out on your first rebuild if you choose to go that way.

That squealing noise is either the front compressor bushing/bearing failed or the compressor clutch slipping on pressure plate and is worn out. Either yields a new compressor assembly needed.

If you choose to do the rebuild yourself then I/we can walk you through the job as its being done. Its simple enough and no special tools needed to disassemble/reassemble the sytem. The compressor is tedious to remove and reinstall.

Orifice tube is in hardline forward (toward front bumper) of the brass nut. You have to remove fitting with green arrow on it to get to orifice tube. Do this when system has been evacuated of refrigerant.

 

[Steve Waddington]

Man, I'm seeing lots of different makes and parts numbers for the compressor! I DO know I need WITH rear a/c. And I'm thinking I should just get the complete kit with the accumulator/dryer, orifice tube, o-rings and oil.
Does anyone have any recommendations on which brand? And how do I look up the original parts numbers, so that I'm sure of getting the right parts?

 

[swathdiver]

Man, I'm seeing lots of different makes and parts numbers for the compressor! I DO know I need WITH rear a/c. And I'm thinking I should just get the complete kit with the accumulator/dryer, orifice tube, o-rings and oil.
Does anyone have any recommendations on which brand? And how do I look up the original parts numbers, so that I'm sure of getting the right parts?

https://parts-catalog.acdelco.com/acesCat.php?

 

[Steve Waddington]

Can you tell by looking if its the proper compressor for rear air? I see a bunch advertised that do not say if they are for rear ac or not!

 

[Steve Waddington]

OK...I'm stumped. I'm having a hell of a time trying to find information. I've decided to replace the compressor, the accumulator and orifice tube, the belt and tensioner pulley...got all the parts ordered. But I can NOT find how much PAG oil to put in! Or how much 134 to
buy. Isn't there some sort of spec sheet somewhere? My Tahoe has the rear air too.

 

[rockola1971]

OK...I'm stumped. I'm having a hell of a time trying to find information. I've decided to replace the compressor, the accumulator and orifice tube, the belt and tensioner pulley...got all the parts ordered. But I can NOT find how much PAG oil to put in! Or how much 134 to
buy. Isn't there some sort of spec sheet somewhere? My Tahoe has the rear air too.

Your replacement compressor will come with PAG oil already inside it. There will be paperwork that says how much if any needs to be added. It will be around 2-4oz if additional needs to be added. The spec for how much r134a is needed for your system will be on the tag underneath the hood. The tag that shows your serpentine belt routing...look around there on that tag and any nearby. Or you can just charge the system using outdoor ambient air temp vs pressure reading of the low side. For instance at 80 deg outside your low side should read 40-50psi with a/c on max and ran for atleast 10min to get a stable reading.

 

[swathdiver]

OK...I'm stumped. I'm having a hell of a time trying to find information. I've decided to replace the compressor, the accumulator and orifice tube, the belt and tensioner pulley...got all the parts ordered. But I can NOT find how much PAG oil to put in! Or how much 134 to
buy. Isn't there some sort of spec sheet somewhere? My Tahoe has the rear air too.

Is your sticker under the hood gone?

 

[Steve Waddington]

Is your sticker under the hood gone?

The sticker is there. Can barely read it, its kinda faded, torn and wrinkled. Same with the belt diagram...but they are there! LOL! I believe it says "R-134 a, with front + rear a/c:
Suburban 1.4 kg (3.0 lbs) or Utility 1.23 kg (2.7 lbs)". But they sell the R-134a cans in OZ, not lbs...so that would be 43.2 ounces. How would I put in the exact amount?
(I'm assuming my Tahoe falls under the category of "Utility", because it's not a Suburban. Right?)