a/c Freon pressure specs

[Unit107]

When I initially read the guage before introducing the r134a into the system, it was reading just shy of 20psi. The guage, unfortunately, is generic, with the "Safe" range indicated as 25-45psi, which I assume is somewhat of an industry standard when it comes to A/C systems.

After introducing the r134a into the system, it immediately jumped to barely over 35psi(the width of the guage dial over the halfway point of the 25-45psi range). With the setup I used to re-fill r134a, there was no way to "force" additional product into the system.

After reading some of your comments here and thinking about it for a while, it is quite possible that several factors came into play (air temp around 85 degrees, accuracy of the guage being slightly off, etc.). I feel fairly confident that the vehicle took what it needed, and that it is reading the appropriate level at this time.

I guess that only last few questions I would have to feel more confident about this adventure are: Are my assumptions correct about the system absorbing the necessary amount of r134a from the can, based on the system I used to refill? And also, if the range is 25-35psi, as perscribed by the manufacturer, what are the negatives of having the system pressurized to exactly 25psi or 35psi, versus being in the middle at 30psi on the nose? If it is that touchy, will I find the compressor sitting in my lap while crusing at 90mph with the A/C at MAX when the pressure is at 36psi(again, if the guage used was 100% accurate)?

I think this discussion has been very valuable(at least to me), as some posts seem to stop short in stating you can do something on the cheap, but don't go into the details on how it should be done properly and what pitfalls others might have encountered while making the fix. Hopefully this will be valuable to anyone looking to take this challenge on.