tracking down a leak

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pishta

pishta

I know I'm right....
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With R134 being almost more than black market R-12 out here in Kalifornia...what can I use to locate a leak? Im down to 20 psi so Im not putting any more "4 in 1" R-134, PAG oil, stop leak (sure...) and dye $20 dollar bills in just to find a leak. Can I pump the system with air from a bike pump to 50 psi and start using soapy water on all the fittings or am I gonna make some Concentration camp death gas?? Its in my wifes 2002 T&C and I cant see any red dye in the engine compartment fittings but I think I have something in the back wheel well for the rear A/C, seems some big lines are going back there. Worked fine until it got hot here, now I got jack....
 
any refigerator repair place (the one in your kitchen) has a sniffer that smells for leaks in their lines.. maybe you could finagle them to look around your car with the sniffer
 
If you have a way of evacuating the system AFTER you stick a foreign material in there, pressure testing is a legit method, but I would NOT use air (water vapor in air)

You have a welder? Co2/ Argon bottle? Nitrogen? You can pressurize with that, but I'd start with 30--50 lbs, and if that does not show up, don't be afraid to go up to 2-300 psi. After all the normal condenser operating pressure is "up there."

But if you don't have a vacuum pump, don't have a way of measuring a new charge, or proper instrumentation to recharge the thing, I'd stick with dye or even as suggested, a "sniffer"

Your "top suspects" are more like to be compressor seal and the high pressure end of the system, but it actually can be anywhere, and not just the fittings, either. Pinhole in a hose, a tube, or the coils. Use a lamp and small mirror to look around stuff, the rear of the evap, if you can get there, and the compressor.

I'm as bad off as you. I've got many pounds of R12, 22, and even some 502 from my HVAC/R days, and the only R-134 I've got is a few cans I bought. If I'd known it was gonna skyrocket, I"d a bought a few more!!!
 
Yes, I have some Co/AR welding gas in a small tank. I can just chuck it up and seep it out until I see 250 psi? Do I pressurize it when running or off? Thanks. The tubes that go back to the rear under the car look pretty chalky and im sure there could be some corrosion down there as the car came from NJ and most of the AL parts, even in the engine bay have what looks like road salt pock marks.
 
Don't run it with "other" gases in the system. You should do this, what's the word, "in a controlled fashion" using a gauge manifold so that you can see what's going on.

Don't do that, again, unless you have a good vacuum pump to evacuate the system. I used to use nitrogen or CO2. Only problem with any "other" gas is, if you later decide to use a "sniffer" then the nitrogen/ CO2 dilutes the refrigerant and makes the sniffer less effective.

When I first started we still used halide torches!!

This is a torch with a hose which creates suction from the flame, and draws the leaking gas up into the flame, which is also heating a piece of hot copper. The gas reacts with that hot copper, turning the flame color. It works much better with R12 than with R22 and some other refrigerants because of the chemistry of R12. I'm sure it won't work at all on the new "green" refrigerants

If you got a "good leak" and got your nose in the "wrong spot" you got a whiff of the very poisonous phosgene gas formed between the flame and the refrigerant, NOT a pleasant experience. That by the way is what Hitler used, some of the time.

leakdettools.JPG
 
Yes, Maybe Hitler was an A/C man before becoming the Fuhrer.....So ill go ahead and introduce up to 250 psi of CO/AR into the low side. If it pops something, it was broke in the first place.....No to try and get to the rear A/C evaporator....
 
Well, I just used some rather bad judgement and topped it off with Propane. I jerry rigged a R134 filler onto a propane bottle with a guage and added to 50 psi and its cool now! Well see how long it (or I) last....
 
A very good way to locate the leak is look for oily connections and parts
It's usually oily around the leak
 
There was no residue around any joints I could see, Im almost positive its in the back condensor or lines to it. Well see.....
 
Ultraviolet dye is what we use. You can probably buy R134A with dye already in it or buy an injection kit. DO NOT put any foreign substances in your system. I have lost three AC machines in the last five years due to butane, stop leak and other crap. We make a customer sign a form now stating that there is nothing foreign in their system and a guarantee of repair to our machine if there is anything they don't know about.
 
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