How does Freon escape if its a sealed system? If it escapes then their is a leak like bad orings right? so replace those also they are like $9 for the pack.

I am no A/c guy but help me understand where it goes. I have had this conversation with buddies about shocks. People think shocks wear out. They do wear out an fail but its not just because the shocks are old. They are a sealed unit and will work forever as long as they do not leak. The fluid or nitrogen does not brake down over time but over time with dirt an movement they loose pressure from cut seals.

Not trying to start an argument. I just want to understand. sorry for the thread interup

 

No problem.

First the idea that any system is trully sealed permently will not happen. Things are man made and imperfect. Some systems can seem to hold a charge forever and for the most part they probably do, but they have lost some charge during thier life but has just not been that much. The small molecules that make up freon can escape during the normal expansion and contraction of the parts that make up the system. You also have to remember that these parts also go from abient temp to high under hood temps everyday also.

I have worked on systems that had to be charged every year, put leak detector in them and everthing even to the point of replacing all orings and new pump seals, because the customers incested that I do it. The system still would leak down. I have had others that only needed to have some charge added after5-10 years. Sometimes it could be the type of hose material used or that the hoses have dried out some or even what day of the week all the parts where manufactured, who nows. Everything manufactured is made to within tolerances and when those tolerances stack up it can cause issues sometimes.

I call it a leak for sure if the system requires charging after a few weeks or months after servicing. Other than that you could chase your tale around for ever or replace everything in the system and maybe get lucky enough to get a system to hold the charge alot longer, but it really isnt worth it. The newer systems have gotten alot better but in an older system and definately any add on system, the odds they will hold many years is greatly reduced.

Hope that helps clear it up some, life is not perfect and neither are the parts we work with.

 

just have to make up your mind and go with it.

 

i have a question for you xcite.
what do you use to find a leak in a system that is empty?
i used to use nitrogen to pressurize the syatem and then spray with soap water.
but the shop with the nitrogen bottle closed, and i am looking for a replacement. i don't like to vent to atmosphere, and i have a car down the street i am trying to troubleshoot with a serious leak.
it will loose 24 inches vacuum in less that 15 seconds. i am pretty sure the condensor was cracked in the accident last fall, but also don't believe in changing parts looking for a problem.

 

Stupid question, could you not pressurize the system with air and use dye?

 

Really the only things I have done or would do is either nitrogen, or a small amount of freon with leak detector. Any other material has the potential to contaminate the system. Straight air pressure can contain high levels of moisture and other contaminates.

 

I'm probably going to get yelled at for this, but you could use propane. Easy, cheap to come by, has a distinctive smell due to the odorants, and you can follow any and all propane leak detection methods.
...Of course, it is flammable, if you have enough leak out, but as a gas it will disperse fairly quickly, so as long as you aren't messing around with a lit cigarette at the time, risk is fairly minimal.
It's also surprisingly safe - if you somehow manage to get a flamable mixture in atmospheric air(and it has a very narrow flammability range), and manage to ignite it, it'll just go "poof", singe your eyebrows off if you're too close, but otherwise not cause any harm*
(* Note: ask me sometime about how I know that )

And, contamination wise, well, it's not really a problem - for one thing, propane works perfectly well as a refrigerant(and is actually /far/ better than R12/R134A - been running it in my AC for a year, and it actually /freezes/ things), and mixes fine the other refrigerants; hell, they actually use it in some of the R12 replacements.

Disclaimer: This is just my 2c. Do some research if you disagree with what I've said here.

 

Ya I know what you mean it does work well as a refrigerent, but depending where you get it from can actually have quite abit of moisture in it. From a liability stand point would never use it for someone elses vehicle, The risk is just to great.

 

and hydrocarbon refrigerants area big no no here is Joisey. if you get caught using them you go straight to jail.
we had a car with hydrocarbon refrigerant in the AC system get in a front end accident back in 93-94 and it caught on fire.
burned a couple of firemen bad when the ac system popped.

the investigation reveled that it was put in and the laws were changed soon after to make it illegal.