Automotive Air Conditioning Information Forum (Archives)

rcmb on Mon June 30, 2014 1:13 PM

my ac leaks and won't hold vacuum. if i run smoke near the parts under vacuum will it suck into the leak so I can see where it is?

pippo on Mon June 30, 2014 8:04 PM

I think its best to provide more background/info. Too little info /history to guess.....

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beware of the arrival

mk378 on Mon June 30, 2014 11:20 PM

Avoid getting foreign substances into your system. It would work better to use pressure anyway as you can hear it hissing out or detect it with soap bubbles, or if it is R-134a, use a sniffer detector. Use a clean dry non-reactive gas. Air straight from a compressor has a lot of water in it, avoid that. If you use cylinder gas (nitrogen, argon, CO2 -- NOT oxygen or flammable gas) you must have a regulator and limit the testing pressure to 150 psi.

Edited: Mon June 30, 2014 at 11:23 PM by mk378

webbch on Tue July 01, 2014 2:20 PM

Interesting idea - worth a try, but only on a pressurized system, not one under vacuum for the reasons stated above. I'd be curious to hear how effective it is, based on the severity of the leak.

Cussboy on Tue July 01, 2014 2:23 PM

Quote
Originally posted by: rcmb
if i run smoke near the parts under vacuum will it suck into the leak so I can see where it is?


No, you use food dye - to watch it getting sucked in - to find a leak in a swimming pool.

If you want to get cheap with leak detection, try dry nitrogen at about 60 psi and use soap bubble solution to detect.