Leak detection and me...

[cswenson218]

New guy...9 months on the job after tech school. 43 yrs old, very serious about being a good tech. I thought finding leaks would be as simple as waving my magic leak detector around and spraying some bubble soap all over the place. WTF? Where have I gone wrong? Time after after time I show up on a service call...add some gas...look for a leak...find nothing. More experienced tech follows up on my call and finds a leak. What is the secret?

[Helioson]

Mindset, experience, equipment(money), patience, willingness to "eat" a few hours, and humility to ask for help from those who have done it awhile.
Get an H10 and learn how to use it. KISS. Slow the down. Stop, look, listen, observe and think. Where are the weakest points. High pressure first, then pressurize the low side (more is better). Spend a few hours on HTALK doing searches. Don't run away from an opportunity to put your skills to work. It's a finite, fixed, sealed system that was more than likely installed by a human...it CAN be found, repaired or replaced. No magic, no problem. Good luck!

Also...spend the time to actually KNOW how the leak detector works...read the manual.

[kamersoutdoor]

Mindset, experience, equipment(money), patience, willingness to "eat" a few hours, and humility to ask for help from those who have done it awhile.
Get an H10 and learn how to use it. KISS. Slow the down. Stop, look, listen, observe and think. Where are the weakest points. High pressure first, then pressurize the low side (more is better). Spend a few hours on HTALK doing searches. Don't run away from an opportunity to put your skills to work. It's a finite, fixed, sealed system that was more than likely installed by a human...it CAN be found, repaired or replaced. No magic, no problem. Good luck!

Also...spend the time to actually KNOW how the leak detector works...read the manual.

Very good advice
I'll add to look for oil

sent from my Samsung Galaxy Note

[dangpgt97]

Dont leave until you find the leak. You know its leaking somewhere. Pressure controls, txv distributors, medium temp evap coils, flare nuts, liquid line solenoid valves, condenser coils....

[toocoolforschool]

Some where in the wall where you can't find it unless you rip the wall open.

[CFESAmasterEGSR]

Make sure your finding out where the other guys are finding the leaks at. Ask lots of questions and LEARN. Great opportunity for learning.

But, yes... Oil/dust residue. Flare fittings if present. I've been bit a few times by access port caps leaking. If you suspect a leak or low, soap those caps before putting your gauges on. Otherwise, sometimes the leak can be found with just the refrigerant gas pressure, sometimes you'll need help from nitrogen to bump up the pressure. Try not to exceed the design pressures of the system by too much. Once you learn where and how to look, it will make a lot more sense. This varies by tech but 80% of the time soap leak detector is all I need.

Good luck!

[CFESAmasterEGSR]

Clarification.... Soak the caps before you take them off, to put your gauges on. Lol

[Snapperhead]

If you dont have a shrader replacer tool , get one , today.

I did a call last year , they kept losing 20 lbs of R22 every 6 months , and the company they been using kept saying they fixed it each time they left.

I got there , took off caps , spit on the shraders , both were leaking.

Within 15 min I had shraders replaced and topped it off. Seeya

Worked on a few other items since then for same customer , but that cooler still going strong and sight glass full.

[Snapperhead]

Look in drain pans for oil in water , oil on fins , soap at all U-Bends on the coil where they are brazed , especially where a cap tube enters. If ubend leaks you can sometimes gently heat it up and shove some braze rod into it the leak.

If the fins are corroded then you have a good chance one of the tubes is leaking in the coil , can be in the middle where its hard to reach. But you must drag over every coil you can , slowly.

Bubbles dont always work in a coil. Sniffer might pick up a leak and no bubbles in sight. That sometimes means its a good size leak , and it just blows the soap off. ( yea those are a royal bi*ch ) You might even have to grab the pliers and rip out some fins to find leak on tube.

You dont always see oil ...... repeat , you wont always see oil.

High Low controls leak on occasion , sniff around cover with detector.

Although very rare , the 3 pins can leak on electric connector on Compressor .... Run Start Common

[A1 Burt]

on simi hermetic where wire hook up to termanile post if you see oiley resadew in side when you take cover off there you go be careful when tightening up post!!!

[2sac]

Wait til you have a leak that's too big to find.

[cswenson218]

Thanks for the advice, everyone...I like what Helioson said: you know it's leaking somewhere...don't leave til you find it. I think a lot of it is just "Don't give up."

[Freightshaker]

Once you check caps before you take them off. Screw them off slowly with your leak detector by it. There is almost always refrigerant under a cap. Just enough to set off your leak detector and let you know it's working. If there is wind or sometimes even a steady breeze you can just about forget about electronic pinpointing. If I can't avoid it I try to wind block as much as possible. Try some different types of bubbles until you find what you like. Lots of guys at my work have their preference. Good luck... Be patient and be prepared to be whipped by some more leaks.

[BALloyd]

I have had to repair several units recently that had bad schraeders including one less than a year old. The cheap plastic caps with missing gaskets did not help.

Rub through leaks are usually tough because they often do not hiss or bubble the soap until you get the two pieces spread apart a bit.

Sent from my SGH-I747M using Tapatalk 2

[jtrammel]

Thanks for the advice, everyone...I like what Helioson said: you know it's leaking somewhere...don't leave til you find it. I think a lot of it is just "Don't give up."

Just ask yourself, what would fengshvac do? I carry a very small spray bottle with bubbles in it a spray all valve stems down before hooking my gauges and after removing my gauges EVERY TIME, once you do it a few times its just a habitual part of the process. And yes it has a lot do do with not giving up, I can do anything some things just may take me a little longer than the next guy.

[2sac]

Just ask yourself, what would fengshvac do? I carry a very small spray bottle with bubbles in it a spray all valve stems down before hooking my gauges and after removing my gauges EVERY TIME, once you do it a few times its just a habitual part of the process. And yes it has a lot do do with not giving up, I can do anything some things just may take me a little longer than the next guy.

Betcha feng just needs to look at a leak and it will repair itself.

[N2fords]

Had one system that was low saw oil but condenser fan sprayed it all over hit it with nitrogen could not find it no pressure drop keep looking finally decided to remove on guage at a time and as soon as I moved the tubing it started hissing. it was factory discharge off compressor at a 90 bend... move things and wiggle it see if it wont make some noise or drop pressure

[Icanfixitall]

Buy a good leak detector, IV used a TIF ZX for 10 years and once you learn how to use it, it will be the best leak detector. Always carry a halide leak detector and soap bubbles. Take your time and you will find it, most leaks are missed because you over rush it.

[koolkahuna]

Had one system that was low saw oil but condenser fan sprayed it all over hit it with nitrogen could not find it no pressure drop keep looking finally decided to remove on guage at a time and as soon as I moved the tubing it started hissing. it was factory discharge off compressor at a 90 bend... move things and wiggle it see if it wont make some noise or drop pressure

To the OP,
Of course you'll be wearing your safety glasses; I had a co-worker grab a line only to have it snap off and a stream of liquid refrigerant shot by his ear. He started wearing them after that...

With water cooled units, the condensers like to corrode and leak refrigerant into the waterside of the coaxial tubing. Shut the water off, put a rubber glove over the end and see if it inflates before tripping on high head pressure cutout. Have your leak detector ready to sniff the inside of the glove when you remove it.

If you confirm a leak in the w/c condenser keep the refrigerant pressure up until the replacement can be made or you run the risk of contaminating the whole system with moisture.

Keep in mind refrigerant is heavier than air, start high and work low. Make yourself a checklist of where you find leaks in the order of easiest to hardest. Start with your eyes and ears first. Look for oil or wind effect and listen for hissing, whistling or sputtering of refrigerant through oil. Don't be afraid to shut off noisy equipment if you are confident you can restart it.
Read the threads on this site regularly and you will pick up a serious amount of knowledge as well as discover who the pros are over time.
:beer:

[Tommy knocker]

Definitely ask where the other guys found the leaks you could not and how they found them, that's how we learn. If its there you can find it. Do not eat hours on a leak test!!! You didn't make the leak. Most will be in obvious locations or oil will lead you to them. Most not all. If its a pump down system use a solenoid magnet and open the LLS valve and equalize the pressure, if its on low side and you leave it pumped down may be very hard to find. I got bit once by a leak on the mounting stud on an accumulator, on the bottom, leaking. Took all day to find it but now I check for that and have found probably 4 or 5 over the years. Rusted accumulators will leak through the pits so check the whole thing not just the connections. Patience and persistence grasshopper. It's a process. You'll get it.