Mike951

I am at the point where I have a leaking system (lost 2" of vacuum overnight). I have heard of others pressurizing their system with nitrogen to leak test and I was thinking the same to hold onto my R-12 stash and I do not want to **** Freeze 12/dye away for obvious reasons. Here is the question:

I have Argon/Nitrogen mix (both inert gases) for shielding gas to weld. Does anyone know if this is a dangerous approach to leak test. I do not want to do anything stupid, but this seems like the best approach to me right now. Details of how to administer the gas to my system will be appreciated. This will probably help a lot of others if someone could outline the procedure.

Also, does anyone out there have Freeze 12 and a hose to put it in for sale? I would rather get this from a Rennister than from Ebay.

Thanks,

Mike

fortysixandtwo

Argon is inert so, I don't see why you couldn't use the mixed gas. I guess the one drawback is that it's a little larger than a nitrogen molecule and may not show a leak as easily, but from the size of the leak you have, it shouldn't be a problem. Besides you'll be vacuuming it out anyway.

Typically you charge to the low (suction) side but you can introduce the gas in either the high or low side. Sorry, I can't give any pressure suggestions for these systems.

dacula951

The regulator that you have for welding purposes may be a flow type regulator rather than a pressure regulator. I purchased an adaptor to go from a nitrogen gas bottle to the oxygen regulator (pressure type) from my acetylene torch. I set the pressure to it's max of 100 psi. I also had a valve between the regulator and where it tee'd in to the line connection to my vacuum pump/pressure gauge. I could then open the valve and watch the system pressure build, then shut the valve when it reached ~100 psi. The beauty of it is that you can then also purge the system with the nitrogen by filling and evacuating a few times - really gets the moisture out.

I also don't see a problem using the mixture, but are you sure it's nitrogen and not CO2? I thought the welding gas is a argon/CO2 mixture. Maybe your gas is for welding something other than normal steel.

If you make a set-up as I described, it's perfectly safe. I've done it many times.

TurboTim

There is a better way.We made a tool that uses smoke from a cigarette along with compressed air that you can use to pressurize your intake or exhaust system.The smoke comes out of any leaks you have and is very easy to track down. Gas or air alone is very hard to use to diagnose lintake/exhuast leaks

IPSC

I think he is dealing with his AC system but this is an interesting idea testing intake and exahust leaks with smoke.

IPSC

TurboTim

It sure works well.You can buy something for Snap-on that costs about $2000 and does the same thing.



Tim

Chris Prack

I would not be concerned in the least with a 2" overnight loss. That could be your guages.

Let's just suppose it is not your gauges. Let's say the system actually lost 2". I still would not sweat it (no pun intended) one bit. You have to remember the seals are intended to keep freon under positive pressure in not vacuum. The seals are being pulled in the opposite direction.

I started working with freon in the early 80's when we could just dump R12 to atmosphere and we did all the time. I once had an 82 Vette that would lose 5-6" of vacuum in 20 minutes but held a full charge of R12 for three years.

As far as Freeze 12 goes, I would not put that stuff in my car. If you don't want to spring for R12 then convert it to R134a. I did my 89 car five years ago and it will freeze you out of the car. You just have to only charge it with 28 oz. instead of the original R12 34 something or whatever it was.