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  1. #1

    Default Gettin the A/C ready for the hot summer

    Today I decided to hook my uncle's set of R134a gauges up to the sub. With the A/C on full blast, max a/c, and the temperature lever as cold as it goes, I was reading around 25psi on the low side and around 158-160psi on the high side when the compressor kicked in. I'm trying to figure out if the freon is at the optimal charging so that I can get the sub as cold as I can. The A/C from the factory has rear air, however, the previous owner of the truck had the rear a/c lines capped off at the T-points in the freon lines in the engine compartment, so as of this moment, I'm running the front a/c only. So, can the A/C do better than it is already? I've looked a little on google for help, but what I've found doesn't seem to be very clear and concise. It all seems to think you have a decent understanding of A/C servicing. Any help is greatly aprreciated in this hot New Orleans weather. ;)

    1991 Chevy Suburban 1/2 ton 2WD w/ chevy SBC 350-3/4 ton drivetrain upgrade w/4.10 gears 200K miles
    2005 Saturn ION-2 Stock 277K miles
    1982 Bronco, 1993 Bronco (sold), 1971 M35A2 Deuce and a Half

    There are 10 kinds of people, those who understand binary, and those who dont...

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  2. #2


    Sounds like your low on R134 gas. The LOW-side should to reading about 30psi and the HIGH-side should be between 180 to 210psi- this is at full charge. The full charge on the Chevy is 3.75lbs of R134.


    2007 Ford E250(Work van) (Ya, Ya, shut up!)
    1996 GMC Sierra SLE 1500 5.7L/4L60E

  3. #3


    I haven't even tried my T.B. A/C yet, I should try mine out myself. Hasn't been hot yet...

  4. #4


    Hmm, 5psi short on the low side and 40ish psi short on the high side...I'll grab a can of r134a to dump into the system..that doesn't seem like a big deal, maybe 10 bucks at the worst.

  5. #5


    I'd get the rear A/C evac'd and hooked up, Suburbans are big trucks and need all the cooling and heating they can get. I notice with ours if I dont have the rear air on it doesnt cool real good up front.

  6. #6


    well, the trick is that it needs to be repaired also. From what I understand from the previous owner, the evaporator(or whichever one the inside unit is) needs to be replaced, and the fan is making a nasty noise also, so it pretty much needs to be rebuilt. I have priced all the parts out, and they're not that bad, I can probably get the whole thing repaired for like 300 bucks, if the lines running from front to back don't need to be replaced. Then I'm guessing like 40 dollars worth of freon will charge it on up, I just haven't gotten around to buying the parts and putting the work in. The evacuation part is going to be the interesting part of it all, I don't think I have a vacumm pump at hand.
    Last edited by Crawdaddy; 05-10-2007 at 08:08 AM.

  7. #7


    as an update, yesterday I bought a couple cans of freon, and charged the system up to 31-32psi on the low side. The high side was somewhere around 225psi,but the truck was in direct sunlight all day so from what I understand, that's ok. Now the A/C does get noticably colder and the compressor doesn't kick in and out like it used to, so I'm happy . I still need to get the back repaired, but at least I can bear the heat a little better with a colder front. Thanks all.

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