Diesel research, man you really know your stuff when it comes to AC. So a vacuum pump is used to remove moisture and water from the lines, its not used to find leaks right? Do they make a can of freon with dye in it that I can charge my system with and check for leaks?
That being said would the links I posted above be good for a vacuum pump and leak tester? I have a neighbor who has a evac machine.
Sorry for all the questions, just tryin to learn.
A vacuum pump could quickly tell you that you do have a leak. It cannot tell you where very easily, since it is sucking inwards. Dye won't likely come out, and soapy water would likely get sucked in. Sniffer wouldn't work because there is nothing to sniffer.
An ultrasonic ear
may hear a whistling noise.
One more thing. Since you will be working with "dirty nasty" older used vehicles, you come into a whole new set of problems. You get a guy with a slow leak like pipster. He gets tired of adding cans every year. He goes down to autozone and finds this stuff called "leak stop". Sounds like the answer to all of his problems. It seals pinholes on contact with moisture.
Only 1 problem! At some point in time his system went completely empty. Moisture got INSIDE his system. That stuff sets up like concrete when contacting moisture. Maybe it sealed off a leaking service port, and now you can't get any readings. Maybe it sealed off his txv/evaporator/FOT or various other small clearances. Or maybe it goes inside of your equipment and gunks up all of your test equipment.
That is where a stop leak detector kit comes into play. Along with filters and solvent flushes to remove it if it hasn't hardened up. If it has, you might end up replacing everything. I lost a gauge due to this. Tore it down and found red high side was plugged solid. Imagine JB weld in the system.
Next problem is god only knows what kind of "refrigerant" is inside the system. Maybe there is air? Air could form an explosive mixture in the right proportions. 40/60 if I'm not mistaken? It will also make your pressure readings look funny. It may also have butane, propane, r12, r22, and a whole slew of other residential or industrial refrigerants. Identifiers are electronic analyzers that tell you what is in there. They are expensive. If you cannot swing that kind of cash, it is best not to put any old refrigerant back into the system.
Yes they sell small cans with dye in them. I don't recommend the small cans due to a few hassles and added expense. Buy a bulk cylinder, properly measure by weight, and use an oil/dye injector. Which leads to the final part of the equation.
They tell you to catch any oil you recover, and measure. Then dump any oil out of old parts you are replacing like a condenser or leaking compressor, and simply add the same amount of fresh new oil back into the system. See any problem? What if it did not have the correct amount of oil in it to begin with? If the entire system was flushed or replaced, you could simply add the fact spec quantity of oil. If it leaked out over time or
backyard_billy has randomly added more, I am not sure how to know how much to add. I know a select few actually have a way of checking, but this is one area where I do not know the answers, and am actively looking.
