air compressor

[HeWhoKillz]

I was taking the air compressor off my car because it hasn't worked for years and wanted to take it apart. I went to unbolt one of the two bolts that holds the metal lines that goes into the firewall and it hissed as if there was air inside. Whats going on with that? I thought those lines had fluid in them not air.

[Blt2Lst]

Originally Posted by HeWhoKillz

I was taking the air compressor off my car because it hasn't worked for years and wanted to take it apart. I went to unbolt one of the two bolts that holds the metal lines that goes into the firewall and it hissed as if there was air inside. Whats going on with that? I thought those lines had fluid in them not air.

AC systems have either R12 or 134A refrigerant in them depending on the year of the car. On a working AC system, the refrigerant is either in a liquid or vapor state depending on where in the cycle it is. If the compressor has not worked in years, the system could still have a charge of refrigerant left.
You should have had the system drained by a shop that can recover the refrigerant before you removed the compressor.
Oh well, so much for our ozone layer

[HeWhoKillz]

Originally Posted by Blt2Lst

AC systems have either R12 or 134A refrigerant in them depending on the year of the car. On a working AC system, the refrigerant is either in a liquid or vapor state depending on where in the cycle it is. If the compressor has not worked in years, the system could still have a charge of refrigerant left.
You should have had the system drained by a shop that can recover the refrigerant before you removed the compressor.
Oh well, so much for our ozone layer

Actually I stopped before it leaked out too much lol. So there is still plenty inside. Whats the difference between me leaving them bolts undone and letting the vapors out and a shop doing it?

[MagicRat]

Originally Posted by HeWhoKillz

Actually I stopped before it leaked out too much lol. So there is still plenty inside. Whats the difference between me leaving them bolts undone and letting the vapors out and a shop doing it?

The refrigerant in the lines never wears out or goes bad. This means an AC mechanic can evacuate (suck out) the refrigerant and recycle it so it can be used in another car.

If you simply let the gas escape, it will drift around in the atmosphere a LONG time. Often, some of this gas makes its way into Earth's upper atmosphere and starts to destroy the ozone (O3) layer, allowing more of the sun's ultraviolet radiation to make its way to the surface. This can negatively affect plant and animal life.

FWIW, the ozone layer is in a constant state of destruction and creation..... but the introduction of refrigerant upsets this equilibrium. R134A is less harmful than the R12, but it still has an effect.

http://en.wikipedia.org/wiki/Ozone_depletion

[curtis73]

Think of the refrigerant in your system like the butane in a lighter or propane in a tank. Its liquid inside under high pressure. As soon as it hits atmospheric pressure it violently evaporates. That violent evaporation is what makes your A/C system work.

Have it evacuated by a shop, then do your work. That evaporating liquid is extremely cold. It can cause violent things to happen, and can give you frostbite in a matter of seconds. Don't underestimate how careful you have to be with it.

[jdmccright]

Uh not to mention that if released in an enclosed space, you could breathe it in...not good for brain cells.

[MagicRat]

Originally Posted by jdmccright

Uh not to mention that if released in an enclosed space, you could breathe it in...not good for brain cells.

The popular refrigerants (R12, R134A) are completely non-reactive, that is, you can breathe them in with no harm done at all. It is non-posionous.

It can suffocate you if you breathed in 100% of the stuff, but there is not enough refrigerant in the car to do that. You could also freeze your lungs if you tried to deliberatly suck it up straight from the pipe. But accidentally breathing it in will do no harm.

The risk comes from the possible presence of other refrigerants. It was possible to get propane-based refrigerants, which are explosive and harmful. These were not widely used, but you can never be sure what's in there