How to find A/C leaks, signed............A Complete Idiot

[67Dart273]

This clown wants us to find A/C leaks by using SHOP AIR. I know a few of you have drained your air compressors. You KNOW the filthy stuff that comes out, right? Dirty filthy water? AND OIL? And whatever else went through the compressor valves. HINT: Please don't do this!!

 

[Professor Fate]

I'm not advocating what he does, but I would imagine he's got an oil/water separator and filter on his compressor discharge- just like for painting. Still wouldn't do it though, personally.

 

[67Dart273]

Water vapor alone is enough to "not to." You will NOT find this "procedure" in any technical book or course.

 

[RustyRatRod]

"The threads don't match"

Yeah, there's good reason for that, DUMBASS. LOL

 

[RustyRatRod]

What's so bad are all the positive comments. Everybody thinks this is a good idea.

 

[SpeedThrills]

A good reason to be careful if someone says they "youtubed" the answer to a problem. Youtube is the source of many answers. Probably as many wrong, as right.

 

[rbkt65]

when i worked a side job, went to an auto auction with the boss. guys were at the gate selling a substitute for r12. it had propane like stuff in it. they demonstrated it and it had a leak that was close to a plug wire and the plug wire arced and BOOOOMMM SHE WENT. we used to use a propane sniffer and the r12 would turn greenish but it was making phosgene gas. very deadly stuff.

 

[Vertex_Jeff]

Because air molecules and refrigerant molecules are the same size...........
If it leaks air, that would be a gross leak compared to the refrigerant. Most refrigerant systems (where the components are manufactured) are leak tested with Helium, inside vacuum chambers. They use a mass spectrometer to detect the helium (or other trace gas) leaking.

 

[pishta]

a little bit o' pressure from your freon and a lot of soapy water in a spray bottle. spray joints and watch for bubbles. Safe and free. There is a misconception of propane blowing up from a leak. It has to pool and concentrate to between 2 and 10% of the air mass. That's a lot of propane in one spot (in an unsealed engine bay no less!) to go kaboom, especially from a pinhole leak in an A/C system. I'm calling BS on that kaboom story.
Makes for a great urban myth on the virtues of R134 but the facts don't jive. We had to take a class on our CNG vans when we got them and one was safety. They took a rifle to the tank and it created a hole, that hole was next to a flame and the flame blew out. They could not get the kevlar wound tank to "blow up" short of putting a C4 charge on it and blowing it up which ruptured the tank AND provided a stable ignition source.

 

[67Dart273]

Also "it could be worse." I recently read an article written by an engineer about the problems and conditions surrounding R410A. He claims that the oil used with R410 retains water VERY aggressively after absorbing it, and that even a deep vacuum "may not" extract water from the oil.

They were talking about a system that had been infiltrated with water, and that it should be flushed out (with a suitable and probably expensive) solvent procedure, then fresh oil added.

 

[Demonic]

Brakclean works for a solvent. But conversions are a PITA. Here's a little story from the industrial side. Long ago, I had a little chiller, lab system goes to -20F on a glycol loop. 58 lb charge of R507. Got a hole in the liquid line, lost the total charge. Found the hole at 250 psi nitrogen, it was hiding at 175. Evacuated with both my 3/8 and 1/4 hoses on the pump. Forgot I didn't have a valve on the pump side at the 1/4" port. The vacuum was at 600 microns. Shut the hose valve and disconnected it at the pump, capped the pump port. Vacuum rose to 1200 microns and took FOREVER to get back to 600.

Nitrogen is readily available at most welding suppliers and HVAC supply houses. Why has the auto industry never adopted nitrogen pressure test like the HVAC industry? No moisture in nitrogen, works well to displace foreign vapors.

 

[Charrlie_S]

Brakclean works for a solvent. But conversions are a PITA. Here's a little story from the industrial side. Long ago, I had a little chiller, lab system goes to -20F on a glycol loop. 58 lb charge of R507. Got a hole in the liquid line, lost the total charge. Found the hole at 250 psi nitrogen, it was hiding at 175. Evacuated with both my 3/8 and 1/4 hoses on the pump. Forgot I didn't have a valve on the pump side at the 1/4" port. The vacuum was at 600 microns. Shut the hose valve and disconnected it at the pump, capped the pump port. Vacuum rose to 1200 microns and took FOREVER to get back to 600.

Nitrogen is readily available at most welding suppliers and HVAC supply houses. Why has the auto industry never adopted nitrogen pressure test like the HVAC industry? No moisture in nitrogen, works well to displace foreign vapors.

I have been using nitrogen for over 40 years. Most auto A/C shops didn't feel it was necessary, when R-12 was 39 cents a pound, and you only needed less then a lb to leak check. I for leak checking, I have soapy solution, propane torch, 3 different electronic detectors, ultasonic, and ultraviolet dye. They all have their own uses.
Another industrial story: we used to add several lbs of R-12 , and then pressurize the system of a lithium bromide chiller (300 tons and steam powered) and use an electronic "sniffer" to find leaks. A lithium bromide chiller operates in a vacuum, and if it develops a leak, it cannot hold the vacuum