After job review - Refrig Evap Coil.

[Slyh13]

So after troubleshooting and figuring out that I had a clogged cap tube. I ordered a new cap tube for this refrigerator and installed it. (a victory refrigerator)

After installation I found a very small leak on one of the elbows in my evap coil. It was suggested that I add some silver rod over the leak to try and stop it. Well I stopped the first leak however 2 more sprang up and then 4 more after the next two.

End story is my evap coil is done and I'll have to get a new one.

Any suggestions on what I could have done differently to have a success rather then a failure on this project?

I didn't add much heat to the coil when I had sweat in the cap tube.

[FEISTY]

You're not telling us enough information to offer educated opinons. What was age of equipment, how was it used and condition of interior of unit itself. Open product stored inside that is " corrosive " in nature will always cause damage throughout the case. Fine powder usually silver in color is evidence of aluminum failure in coil. If unit is older your chances of a repair are slim. Fix here...leak here...fix here..leak here nd so on. Next time charge system with nominal amount of nitrogen and trace amount of ***** used. Look for loss of pressure over time. Use sniffer without fan running to check for hidden leaks. Rating the quality of an evaporator coil comes with experience. Just like you went thru. Cheaper in the end to quote a new coil than cost of callbacks, materials and reputation. Good luck.

[Slyh13]

You're not telling us enough information to offer educated opinons. What was age of equipment, how was it used and condition of interior of unit itself. Open product stored inside that is " corrosive " in nature will always cause damage throughout the case. Fine powder usually silver in color is evidence of aluminum failure in coil. If unit is older your chances of a repair are slim. Fix here...leak here...fix here..leak here nd so on. Next time charge system with nominal amount of nitrogen and trace amount of ***** used. Look for loss of pressure over time. Use sniffer without fan running to check for hidden leaks. Rating the quality of an evaporator coil comes with experience. Just like you went thru. Cheaper in the end to quote a new coil than cost of callbacks, materials and reputation. Good luck.


Ah yes ... sorry about that, one of my flaws in life is I always try to get away with by saying the least amount of information.

Anyway the machine is 15 years old. It was clearly never taken care of. When I first was to work on it I found that the condenser coil was completely clogged with dirt. The whole system was pretty dirty, covered in grease and oil.

I have a suspicion that the tech before me might have added contaminated refrigerant to the machine.

The original complaint was that it wasn't getting cold enough. I found that the top pass in the evap coil was iced up. First thing I thought was either it was low charge, blocked, or there was a small leak.

After my initial trouble shooting i found that the cap tube was clogged. I tried to purge with nitrogen. It opened, then it closed again then it opened then it clogged again and i couldn't get it open. I tried to vacuum the blockage out and that didn't work either. I had no leak in the system.

I tried to be as careful as I could and I took the evap coil out. I quickly took out the cap tube and cleaned it up. I quickly got the new cap tube back in.

I pressured tested and noticed I was losing psi very slowly. Tossed on some bubbles and found a crack so tiny i couldn't even see it on one of the coil elbows. Actually the sleeve that the elbow goes into.

My boss suggested I just try to run some silver rod down it. Tried to no touch any other part of the coil with the flame, but every time i fixed one leak a new one came up.

I'm basically chalking this up to and old system that I really couldn't have done much else to fix. I think a combination of abuse and age created unsalvageable conditions.

Basically I'm looking for advice on anything I might have been able to do to save the coil.

[nike123]

When you testing for leak, what is your test pressure?
What is use of that unit?

[Slyh13]

150 psi was my test pressure for the coil. Not sure what was done with the unit over it's life time. They were holding bread in there currently.

[FEISTY]

Your explanation of what you found, how you approached the problem and what you did to solve it is refreshing. You were backed against a wall from the beginning. I have begun to use Calgon's product to seal small difficult leaks as a last ditch attempt before changing the coil. I am not a fan of adding " miracle fix-all " products to a system but when cost is a factor, do what you must. I am now 3 for 3 in the success column. 2 were R22 units and 1 was R134. The R134 is a cap tube unit. It worked in all three situations. Follow the directions, evac the unit, chance the dryer and add the product so the vacuum state pulls it in. Saved all 3 customers quite a bit of money. Lastly you are located in my area. If I can ever be of any help...even to just bounce off a problem, please feel free to contact me. Email is jeff@feisty1.com. We can do the other contact info later. Good luck and have a great day !!!

[Brian_UK]

I suppose the only thing that might have helped was covering the surrounding areas of pipework/coil with wet rags to try and localise the heat.

To be honest with small coils you often end up chasing your tail trying the repair them.

[tonyhavcr]

So after troubleshooting and figuring out that I had a clogged cap tube. I ordered a new cap tube for this refrigerator and installed it. (a victory refrigerator)

After installation I found a very small leak on one of the elbows in my evap coil. It was suggested that I add some silver rod over the leak to try and stop it. Well I stopped the first leak however 2 more sprang up and then 4 more after the next two.

End story is my evap coil is done and I'll have to get a new one.

Any suggestions on what I could have done differently to have a success rather then a failure on this project?

I didn't add much heat to the coil when I had sweat in the cap tube.


:o Wow how many times I have seen this
too many on 35 deg reach inn the copper is porous from open lemons, salad dressing not stored well the leaks where all ready there you could not see them But when you kiss it with heat they open you can try rages or heat past I did they still open so when I fine a leak on a older evaporator reach inn 35 deg I replace it and save the headache.

[tonyhavcr]

After thinking on it the cap may of just been plugged w/ice from the evaporator leak, did YOU test for it?

[Gary]

Brazing a coil is delicate work. I have had some limited success by pulling a slight vacuum on the coil before brazing, so that the brazing material is sucked into the leaks... but generally you are better off replacing the coil.

[Frostyguy]

Typically cap tubes just dont plug up unless drier releases, or as in your case, your system probably ran in a vacuume and sucked in contaminants.

You said you used silver solder. The melting temperature on that is 1500+degrees. You where in tight quarters. Why your boss said to drip that down is beyond me, with those temperatures and flux you needed to use.
Staybrite #8, has a melting temperature of 400degrees and is more likely to do less damage.

Now, bare in mind Im not completly sold on this next suggestion but its worked for me two out of two times Ive tried it, but there is a high temperature epoxy that is rated for our industry.. If you have a clean surface, mix it right and use a hot air gun, (not tourch), it seems to work.

[nike123]

Now, bare in mind Im not completly sold on this next suggestion but its worked for me two out of two times Ive tried it, but there is a high temperature epoxy that is rated for our industry.. If you have a clean surface, mix it right and use a hot air gun, (not tourch), it seems to work.

I think it is rotten away and any fix on one place lead to leak on other weak place. Time to change. ;)