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Discussion Starter #1
I am trying to recharge my A/C system but can't seem to find out how much R-134A to use. I don't want to overfill or underfill the system, so does anyone know how much to use?
 

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are you getting any cold air at all? There is a kit they sell to check the pressure but not worth $100 for it. It takes 2 to 3 14oz containers. If it's empty use all 3 if not just 2 will be fine. They sell the recharge kits at autozone. hose is like $20 and containers are like $10 I just did mine not to long ago spent about $50 total.
 

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They sell a kit at Autozone or Pepgirls that comes with a small gauge to test pressures... It reads like yellow (low), green (good range), and red (over filled).. Pretty much a no brainer if you follow the directions...
 

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Discussion Starter #5
No, I wasn't getting any cold air. I drained the A/C System when I swapped my engine last month so they system is empty, thus needing a recharge.

I have the Polar Air recharge kit from Autozone, but the directions are pretty vague. They say to fill the system with the proper amount of 134.

I filled it last night and to get the air even cool I used 2 cans (15oz each). That put my pressure at 75 psi or in the red zone (danger). When the system was in the full/safe zone it wouldn't even get cool.
 

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well.. I heard that 38 ounces is the magic number, but don't quote me... so I could see how you used two cans....
 

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Phantom5oh said:
No, I wasn't getting any cold air. I drained the A/C System when I swapped my engine last month so they system is empty, thus needing a recharge.

I have the Polar Air recharge kit from Autozone, but the directions are pretty vague. They say to fill the system with the proper amount of 134.

I filled it last night and to get the air even cool I used 2 cans (15oz each). That put my pressure at 75 psi or in the red zone (danger). When the system was in the full/safe zone it wouldn't even get cool.


I bought the Polar kit yesterday from Autozone too. It looks good for $37, which the gauge and stuff. Hope all goes well, though it still need to fix my front vent problem.
 

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There is a sticker under the hood, some place that tells how much the system needs.
 

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Discussion Starter #9
streeter69 said:
There is a sticker under the hood, some place that tells how much the system needs.
My car doesn't have a sticker. Either the previous owner removed it or it has come off over the years.
 

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If you drained the system, wouldn't you need to draw a vacuum before refilling it? That might explain why you have more than enough pressure but not much cooling.

Dave

Edit: I just talked with my brother (getting to be an expert with A/C, has his own tools and has been doing a bunch of friends' cars). If the system was vented, then you *must* pull a vacuum before recharging, or you will not get satisfactory results.
 

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I’m in the same boat… What is a do-it-yourselfer solution for evacuating the system?
 

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CobraR77 said:
I’m in the same boat… What is a do-it-yourselfer solution for evacuating the system?
You need a vacuum pump. Not horribly expensive, but still going to set you back a couple hundred bucks for the right one. Cheaper than going to most shops, especially if you have multiple cars.

My brother decided to get the federal R-12 license, costs $20 and you take an online test :D. He buys R-12 off eBay. You shouldn't need a license for R-134A?? Maybe that's a state law...

Dave
 

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Discussion Starter #17 (Edited)
HairyCanary said:
If you drained the system, wouldn't you need to draw a vacuum before refilling it? That might explain why you have more than enough pressure but not much cooling.

Dave

Edit: I just talked with my brother (getting to be an expert with A/C, has his own tools and has been doing a bunch of friends' cars). If the system was vented, then you *must* pull a vacuum before recharging, or you will not get satisfactory results.
I should have thought of that. It only makes sense, because air is compressible fluid. Trapped in the system it would create a higher pressure and make the compressor work twice as hard.
 

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Musti94 said:
I bought the Polar kit yesterday from Autozone too. It looks good for $37, which the gauge and stuff. Hope all goes well, though it still need to fix my front vent problem.
That Autozone Kit worked great!! No complaints. I used up 2 cans completely. Im cool now, plus i got my vents to work :p
 

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dudes i was just trough this. My low side fill valve went bad last summer and my high side went bad this summer, so if one of yours goes bad fix them both at the same time. you can replace the valves only, they're cheap from the dealer, and i just switched them out with a pair of pliers. Yes you do need it evacuated to about 30 lbs of vacum before you charge it. Plus if the system is opened up you should pull vacum for at least a half hour to pull any possible moisture out. and yes the capacity is 34 oz. The first time i had to recharge it i did it myself with the small cans and i think i put like 36oz in(three 12 oz cans). The second time my friend did it at the shop with this all in one unit that put 34 oz dead nuts in.. damn its freezing now! hope the advice helps
 

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This just popped into my head. Our systems hold 34 oz. of R134a max. I put 2 cans last night. MOst of u say that 2 is enough but in my kit I have 3 cans. Each can has 12 oz of R134 + 3 oz. of Oil Charge. Total of 15 oz. So technically I put in 24 oz of R134 into the system. Should i put in the 3rd bottle to make it 36 oz? The AC air was somewhat cool, but not cool enough to be satisfied. I just dont want to over charge the system.
 
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