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Hmmm...something doesn't seem right. Went out there, with compressor on, the pressure was steady at about 25. Emptied the can, only about half full because used on another vehicle as well...but the pressure never went up. Stopped filling and checked pressure regularly, didn't increase, so continued to fill. Probably only raised about 2 psi, actually. Ambient temperature is about 78. Never got above 27psi with the addition of the remaining 134a.

Do I just get another can and continue? That seems kind of scary...
 

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Hmmm...something doesn't seem right. Went out there, with compressor on, the pressure was steady at about 25. Emptied the can, only about half full because used on another vehicle as well...but the pressure never went up. Stopped filling and checked pressure regularly, didn't increase, so continued to fill. Probably only raised about 2 psi, actually. Ambient temperature is about 78. Never got above 27psi with the addition of the remaining 134a.

Do I just get another can and continue? That seems kind of scary...
Unless the AC is clearly not doing its job, you probably don't need to do any recharging at all. These kits are mainly for the DIYers to feel better about doing something themselves, but in reality they don't do more than add a bit to the system, which may or may not need it. I'd let an AC shop do a full service if I felt my AC wasn't cold enough.
 

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Hmmm...something doesn't seem right. Went out there, with compressor on, the pressure was steady at about 25. Emptied the can, only about half full because used on another vehicle as well...but the pressure never went up. Stopped filling and checked pressure regularly, didn't increase, so continued to fill. Probably only raised about 2 psi, actually. Ambient temperature is about 78. Never got above 27psi with the addition of the remaining 134a.

Do I just get another can and continue? That seems kind of scary...

If you used the can on another car...you don't really know how much is left in the can for there is no guage to tell you the remaining amount inside can. Did the first car blowing out colder air after charging?

Each full can will yeild x amount of r134a. Product info say that usually the small can--2 oz. is usually enough for charging. So if you are way under then you may need more.

You mentioned getting 2 readings: one with the compressor on and one off. What are you getting now on the 2 readings? http://www.idqusa.com/faqs.php?faq=90&faq_id=90&category_id=7
 

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Some background: Freon is a term for a class of chloroflurocarbons (commonly R-12) which is no longer used in auto AC systems. Most now use R-134A (a kind of tetrafluoroethane) which I haven't heard referred to as ""freon", although it's likely that term is still used coloquially. At any rate, R-134A is what you would find in auto parts stores.

R-134A has a smaller molecular structure than R-12, and is therefore slightly more prone to leakage. I STRONGLY recommend that you take the car to an AC shop (not the dealer) and have them do a leak test, then fill it for you. The cost should not be very high, and it will be done right.

I decided some time ago not to just slap a filler gauge set on my AC and mickey-mouse it. I leave the AC recharge work to people who really understand the systems.

I do replace my own AC components or even complete systems (done it on three cars and saved a ton of money) but when it comes to re-charge time, I take it to a pro.
Good advice, another thing to consider is a restriction due to a leak. R-134a uses POE oil which has a high affinity to attract moisture from the atmosphere. One thing I will say is do not allow any mechanic to add dye to your system to leak check. Dry nitrogen and a trace charge of R-22 will allow any competent mechanic to find the leak with an electronic leak checker and soap bubbles. Dye makes a huge mess and in every instance I've seen it used causes restrictions in the metering device or problems down the road. In order to check a system correctly you have to have a manifold gauge set to check High and Low side pressures. The ambient +30 rule is old school and you can't go by that, you'll usually be over charged. The truth in the matter is you can't diagnose a system over a forum conversation, you can only guess.... unless the mechanic working on the vehicle has all the necessary tools.
 

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If you used the can on another car...you don't really know how much is left in the can for there is no guage to tell you the remaining amount inside can. Did the first car blowing out colder air after charging?

Each full can will yeild x amount of r134a. Product info say that usually the small can--2 oz. is usually enough for charging. So if you are way under then you may need more.

You mentioned getting 2 readings: one with the compressor on and one off. What are you getting now on the 2 readings? IDQ - Auto A/C Products & Sealing Solutions
You may be able to check if there is liquid in the system by taking the ambient temp and converting pressure to temperature. You can do this with the car turned off.
 

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Hmmm...something doesn't seem right. Went out there, with compressor on, the pressure was steady at about 25. Emptied the can, only about half full because used on another vehicle as well...but the pressure never went up. Stopped filling and checked pressure regularly, didn't increase, so continued to fill. Probably only raised about 2 psi, actually. Ambient temperature is about 78. Never got above 27psi with the addition of the remaining 134a.

Do I just get another can and continue? That seems kind of scary...

What's you Head pressure reading?
 
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