So had to recharge my AC for the season. Luckly I had a fresh can laying around. Only put in the one can and got nice cool air. The pressures settled at 30psi low side and 150 high side. I was thinking they were supposed to be around 38/40 and 180 but its been a season or two since I've charged this '08 HHR. It was one can so thinking I'm a bit short on freon but it is blowing nice and cool atm. Does anyone know what my pressures should be at once it is running stable?

 

im no expert but rule of thumb i believe is static pressure ( not running...both sides equal) should be about ambient temp. I got a cheat sheet my son sent me on high side pressures at various ambient temps. system runnning....ill send you copy.....get coffee first...lol
also, if you are not afraid to use it....there is a much better refrigerant to use than R134...it is called Duracool....little pricey but it cools way better with less of it and lower high side pressure.
Now....it is mostly propane...6 oz. equals 17 oz. of R134....zero ozone depleting agents.
Go to their website and read about it. Oddly enough...its made in Canada. I have had it in ‘85 Vw Jetta for about 4 years now. No issues....it gets really cold!

 

R-134a pressure chart

after system runs a while....you need to note pressures and shut it off and see how long it takes to equalize...(checking for retrictions)

 

That isn’t odd, we do have some cool inventions up here!

 

no offense...lol....being from Alabama....Canada just dont seem to be that hot like here. I will say...my old jetta was designed for R-12 and R-134 dont work very well and head pressure with that is a lot higher. That Duracool fixed all that...cools better than R-12 even and head pressure down almost by half so less load on belts and my little 4 cyl. tired engine...lol

 

It’s in the mid 80’s outside today, and we have had temperatures over 100 degrees F some time in June and July, many of us even have central AC in our igloos!

 

Lol....ok, ....i got it. I just dont get up your way to much.....to far and snakey....lol

 

We have had people stop and ask where the ski hills are , in July.

 

Lol...yeah....its a “stereo typing thing”.....you can imagine what our is down south here...lol. I got friends in northern Indiana that have all kinds of mental pics of how things are here....some even scared of traveling south...lol. Thats ok too....ever body cant live down here anyway....
...first time i went to southern California....I was kind of “taken back” cause people wouldnt talk to you unless they knew you...my thought were, dang...whole state full of A## holes....down here, everbody talk to you...maybe not what you want to hear but they will talk...so strange to me back then

 

Of course, the real answer is "fix the leak". I have NEVER had to add refrigerant to a car AC, including my 1999 Mazda. R134 does not just disappear, it does not need routine replenishing.
I have had to replenish my 30 year old home AC, after The AC guy hooked his gauges up and broke the Schrader valve seal.

From wikipedia: https://en.wikipedia.org/wiki/HC-12a
Because of its high flammability, it is unacceptable to replace R-12 with HC-12a in the United States.[2][3] Thus its use in public transport vehicles is illegal in the United States since 1990.[4][5]