there is something i forgot to mention in my last post about my ac project. i'm good to go right now but i am not too sure about the amount of freon you actually get from a 12 oz. can. book calls for 26 oz. for my 97. sounds easy with 12oz. cans. 2 cans plus an educated guess for the last 2oz. as i put my ac tools away i decided to see where i stand with my refill. an empty can weighs 3.42 oz. i have two confirmed empty cans that i weighed with my kitchen scales. full can weighs 15.34oz. after about 40 minutes of emptying two cans i weighed them. one weighed 5.36oz and the other weighed 4.06oz. i'm sure after about 20 minutes each can i got out what should have been 12oz. dosen't look like 12oz. came out on each. was there enough pressure left in the can to overcome lo side pressure? do we get 12oz. freon from each can or about 7 or 8? this is a huge question in my ac project. not much wiggle room with 134 as there was with 112. this is a very important part of the project for me. i'm getting mid 50's vent air which is much better than what i started with. ok for this year but i'm gonna revisit this project the spring of 2024.to try to get better. as stated in my other post i seemed to fix the hot drivers side air so something went well. i'm sure some members have more experience with these cans than i do but it seems like i'll have to do some math to get the right amount next time.

 

One fairly common method of getting more out of the cans is to warm the can during fill, either by wrapping with warm wet towels or by placing the can in a bucket of warm water. How warm? Haven't found a good reference. Not boiling, I don't think, but can pressure drops precipitously as the gas goes out and temperature drops.
I know it's 'wrong' and frowned on by many, buy I've had better luck filling to pressure than I have by filling to fixed quantity.

 

had the cans on the intake manifold for a while. it's warm there but how much i don't know. pressure was looking good during the refill so thats when i stopped. went for a ride today and all was very nice so far. talked to my mechanic friend and he said bring it anytime and he'll evac,vacuum, and refill with his snap on machine. he's not a huge fan of the cans. thanks for the reply

 

Even though its not recommended, if you're careful, you can get the last 1 oz or 2 out by turning the can upside down AND just pressing the button for a half second, or a full second. DO NOT PRESS AND HOLD until its empty. That's how you damage components. Just a half second to one second press and release and you'll be OK. OR, since it's drive by wire, you can't grab the TB and rev the engine by yourself. So see if you could get someone to rev the engine up while pressing and releasing the button while can is upright. Press while revs are up, release when revs drop.

 

hi grinder11. what button are you talking about? don't see any buttons on the cans i have.

 

The button I'm referring to doesn't come on the cans! It's the part that screws onto the can, with the hose you connect to the low side port. I call it a button, maybe others call it something different.....

 

Your friends recycle/recharge machine is definitely preferred over individual cans for a few reasons.
1. you will recover the R134a rather than release it into the atmosphere.
2. you will get a weighed amount of charge rather than trying to get the correct amount with individual cans.
3. you will not get air into your system (assuming the recycle/recharge machine has separated out air and other contaminants). Charging with individual cans requires a bit of care to be sure you purge out any air as you change from can to can.