Hey guys,
I’ve taken my car to a shop twice because the air conditioning isn’t cold. The shop stated both times that there is a freon leak, but said he couldn’t find it. The second time he refilled the freon at no charge.
Can anyone recommend a trustworthy shop that specializes in A/C repair? Or maybe a maker that can replace all the gaskets / o-rings?
Car is a 2002 Subaru WRX with a 2008 STI motor in it.
Thanks!
Where are you located?
There are rumors that if you bring your car to the space complaining of hot a/c the “Allen Fairy” will show up and all of your A/C problems will fade away like your sweat on a hot day.
If you’re interested in doing it yourself, they make a Freon that has a UV (and/or visible) dye in it, that you can add to your system and then find the leak. I would recommend doing that before just replacing all of the gaskets/o-rings.
If you can’t find the leak with the dye method that’s a good sign and means that you have a small enough leak you can use a refrigerant sniffer to find it, and with a bit of practice you can get really good at find leaks with them. Failing access to the leak sniffer, soap and bubbles is good if you know generally where to look.
We have both the UV dye and the UV light at the space. If your system is empty you can also fill it with shop air to find the leak.
We also have 3 sets of manifold gauges, numerous adapters, excellent venturi-effect vacuums, and more!
A while back I had an A/C problem that ended up being a leak between the firewall and the dashboard. Mentioning because if your car is designed where some of the connections are inaccessible like that, your problem may not be locatable be any of the above means. But I would follow those troubleshooting and diagnostic suggestions first to exclude all obvious/visible/accessible potential leak sources.
I would highly recommend pressurizing with nitrogen and not shop air. If not nitrogen then some other sort of inert gas. Some electronic leak detectors will locate a leak of a 1/4 ounce a year leak. You can also use spray bubbles. I personally do not like the dye. That’s my personal preference. Same goes for leak seal. I won’t touch it. To do a good leak check you will need to be in an environment that is not to windy with an electronic.
Perhaps there should be a discussion about adding nitrogen to our gases we get from Metroplex. Nitrogen is cheap by the way.
Definitely NOT interested in doing this myself. Have cash for someone else to get it done.
Located in Irving / Las Colinas.
Is putting nitrogen into tires still a thing? Might a lot of it get used that way?
Anhydrous N2?
I don’t know anything about nitrogen detection, but I know you can get a helium leak detector. Soapy water and a spray bottle works just as well. Total submersion works better, but is impractical.
Nitrogen molecule N2 is anhydrous since it has no water molecule, maybe you’re thinking of anhydrous ammonia NH3, which is commonly used as a nitrogen fertilizer.
You put a trace gas in then pressurized with nitrogen.(not liquid) Shop Air has moisture, that’s the last thing you want to introduce to a system that doesn’t do well with moisture.
Actually it is not that great at finding leaks. You would think so but air bubbles tend to stick to the surface of the material submerged. Now if it was a larger leak, not hard to find.
I have done it a few times
If you’ve got a leak, you’ve got moisture. Replace your receiver driver during the leak repair. In the meantime, shop air won’t hurt anything any more than it’s already damaged.
Not necessarily. If it is still pressurized, it will not likely have moisture. If it is flat, then yes it will.
Will it be fine to use shop air? Yes probably but I wouldn’t to it. But that me as a professional.
We’ve recently did a leak test on some ac coils with suspected formicary corrosion, but definite leaks, and the helium leak detection was only good to narrow down the leak to a few square inches. The submersion test got it to the exact vane 2/2 times. More leaks were located, but only two precise locations were verified without removing the vanes.
Soapy water spray didn’t really work for our application. I’m guessing it’s because the aluminum vanes are difficult to get a water seal on with just spray.
I think we only have the capability to run up to more than 1k psi. I can ask about the precise pressure used if you care. If you need more than that to find the leak, then it’s probably not leaking in a car ac system either.
Overall, pulling the ac components out of the car for leak testing is pretty far down the list for most people I think. But if it comes to that, full submersion definitely works.
Looks like the Makerspace fairy and Davis automotive are your choices
It’s apparently leaked down enough to stop working at least twice, this early in the season. I suspect it probably went flat over the winter. Either way I’d vacuum the system down, charge with shop air, and go leak-hunting, then replace the receiver drier along with the leaky component. $5 for a new receiver drier on a 15 year old car is, at the very least, good insurance following a leak. Not to mention you’ll have to replace something eventually, and that means draining the system and opening it up to atmosphere anyway.
That’s my opinion as a former professional.
Love Instructables, gladly pay the $25/yr subscription fee so I can download the files. Lots of ideas and save because there is a part of something I’ll want to reference in the future.