Wurth's A/C stop leak & A/C leaks

[virginoil]

1. Can air get into Auto A/C systems ?
I understand that the A/C system is under higher pressure (than the outside air) the R134A gas inside would be pushing outwards. How then can the A/C system allow the air to enter if the air outside the A/C system is at a lower pressure ?

2. Possible cure for minor R134A gas leaks.
Any BITOG's used this product, Looks the real deal, check the link
http://www.wurth.com.au/catalogue/A04_0604.pdf

This is the same product marketed worldwide by Wurth's.

Claims it has no polymers wont gel, hardened or clog A/C systems or any A/C recovery equipment.

I understand most Professionals warn not to use any stop leak in A/C systems, Is this one different ?

It is around $100. AUD. I am tempted to give it a go as a top up.

 

[porcupine73]

I've heard issues with stop leak products too. It can also gums up the vacuum pump and other equipment used for recharging.

Maybe air can get in if there are any leaks on the suction side of the system. Also any leaks may also pull in air.

It may sound weird, but that does happen. It is a common issue on clean dry compressed air systems, where mysteriously water starts showing up in the system, and it's because of a small leak somewhere that draws in atmosphere.

 

[mechtech2]

Air won't get in if there is a positive pressure in the system.
For $100, I'd rather add refrigrant a couple times a year.
If it needs more, then I'd fix the massive leak.

 

[porcupine73]

If there are any leaks in the system, air can get drawn in, even though the system is at higher pressure than atmosphere.

It’s counterintuitive, but Fick’s Law explains why water migrates from high-humidity outside air into dry compressed air even though air is coming out the leak. “It’s hard and for some people, impossible to believe, but it’s true,” Stroup says. “Is your water problem bigger when the humidity is high or it’s raining? That’s why.”
http://www.plantservices.com/articles/2006/132.html