Although the most popular type of Freon r134a is supposed to be environmentally friendly it was still not designed to be released into the atmosphere in large quantities.
If you continue to recharge your AC and it continues to leak out, this is not good for you or the environment.
Finding AC Leaks
This next page talks about finding large car AC leaks in automotive systems. Also included on the page are links to tools to help you solve the problem once and for all.
AC stop leak kits
The AC stop leak works best on the low pressure side of the automotive A/C system.
When the system is turned off on a hot summer day there could still be 100 PSI of pressure in the low side. But during normal operation the low side pressure falls down to about 35 PSI. This gives the air-conditioning stop leak a fighting chance to take hold and stay in place.
AC leaking Freon on the high side will usually need a physical repair of the problem. High side pressures can reach over 250 psi. In most cases stop leak will not be able to stay in place in the affected areas under these types of pressures.
Also keep in mind if you go overboard and install too much of the stop leak it could actually harm the compressor and plug up critical areas of the car air-conditioning system.
My advice is to always try to find and repair the leak. In some cases the repairs can be miner such as a leaking O-ring or even a loose connection that just needs to be tightened. Under those circumstances there is no reason to install AC stop leak when a permanent repair is so easy.
This next link will take you there from Car AC Leaking Freon to the automotive air-conditioning section.
There is lots of good stuff right here on this blog. Visit this next link for more of the latest post right here on the online auto repair blog.