freon question!

[shodid]

I have an 96 Tahoe, im bout to put a new compressor,drier and orfice tube in, and I need to know how many pounds/cans of freon I need? I dont have rear A/C!! my sticker dats normally on the drier is gone dat tells me how much!! i know its between 2-4 just wanted be on the safe side!!

[MT-2500]

36 oz. of R-134a
3 cans if 12 oz. cans.
But only use the pure R-134a stuff.
No added oil or stop leak crap.
Check your new compressor for added oil.
Some come with a 10 oz slug of any kind of oil.
If so drain it out or totally drain compressor before installing.
You are supposed to drain and measure the oil in old compressor and add to system according to what old compressor had in it..

The total system uses 8oz. pag 12345923 oil.

When replacing comp add 2 oz for compressor and 2 oz for dryer.
And allow a oz or hair more for any oil lost from leaking system.

The Napa web site has a good chart in a download PDF on it.

But they do not call it Freon any more.
It is called R-134a
Good Luck
MT

[MT-2500]

http://napabeltshose.com/downloads/d...s&view=napa_hc

[j cAT]

Originally Posted by shodid

I have an 96 Tahoe, im bout to put a new compressor,drier and orfice tube in, and I need to know how many pounds/cans of freon I need? I dont have rear A/C!! my sticker dats normally on the drier is gone dat tells me how much!! i know its between 2-4 just wanted be on the safe side!!

to do this work you will need a vacuum pump and a set of refrigerent gauges then you will be sure to have added the correct amount of r134.....with air traped in the system you will get high pressure readings and very poor cooling....vacuum the system for 6-8hrs...before vacuuming the system pressurize the system with nitrogen and check for leaks...add 150psi to system then use soapy water check for bubbles and pressure loss..adding a small amount of r134 to check for leaks is ok but not as good as nitrogen...

my GM vehicles use PAG 150 check that this is good for you on your vehicle



use refrigent oil on all O rings/gaskets, and replace all rubber seals

adding slightly too much oil is better than not enough.....too much reduces efficency.....too little will cause the refrigerent to leak out faster..

[reekor]

Vacuum the system for 6-8hrs ? Not sure what you have for a pump but normal time for vacuum is 15 minutes or 30 minutes in a really humid area. I personally vacuum for an hour. Impressive post I have never seen anyone on a forum give the advice to use nitrogen for leak detection.

The only thing that I can add is, if you don’t vacuum. Moisture, Pag oil, r-134A = hydrochloric acid. Which starts eating your rubber hoses from the inside out and sending black sludge throughout your A/C system. This is known as “black death” since it’s nearly impossible to flush out and requires replacement of the whole A/C system. On the mild side of things, moisture in you’re A/C system will crystallize on your orifice tube making you’re A/C not cool as well as it should.

Originally Posted by j cAT

to do this work you will need a vacuum pump and a set of refrigerent gauges then you will be sure to have added the correct amount of r134.....with air traped in the system you will get high pressure readings and very poor cooling....vacuum the system for 6-8hrs...before vacuuming the system pressurize the system with nitrogen and check for leaks...add 150psi to system then use soapy water check for bubbles and pressure loss..adding a small amount of r134 to check for leaks is ok but not as good as nitrogen...

my GM vehicles use PAG 150 check that this is good for you on your vehicle



use refrigent oil on all O rings/gaskets, and replace all rubber seals

adding slightly too much oil is better than not enough.....too much reduces efficency.....too little will cause the refrigerent to leak out faster..

[j cAT]

whenever the system is open for a long period of time and adding oil to compressor at install air/moisture needs to boil off this takes time...if system just lost refrigerent much shorter vac. time is ok...the black death is a costly error when repair is not properly done...