Air Conditioner Aluminum Line Leak Repair

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This A/C line owns me.  Need some tips from you guys.I had to rework this connector due to space constraints with an intercooler.This original aluminum line entered from the rear through the front and sealed to the condenser with an O-ring.  The metal block was simply a bracket (it was not a part of the sealed system) that held it the aluminum line place.I had to turn the bracket into a right angle manifold and welded around the whole thing to seal.  It held to 50 psi when they vacuum leak tested it but sprung a pinhole leak when they when to charge it.I assume it was just inadequate penetration.  I will go over it again with a TIG welder.For you guys in the know, do you have any tips?  I am just going to clean it very well and go over it all again.  Is there any way to coat/braze this easily so I can guarantee it's all sealed up?  How do A/C professionals seal joints?Last edited by TeCKis300; 01-04-2008 at 09:39 PM.
Reply:i have tryed AC lines never had good luck with them.(had one or two that worked)... but is better to buy new and not worry about leaks (high pressure/with oil) will make or break the job. most lines are too contaminatedto get a clean weldgood lucklow heat and small filler
Reply:Silver soldier and a B-tank. B-tank is acetylene and oxygen mix I think.And the silver soldier comes in flat rod looks like brazing rod only flat.You can get the rods a Grainger.Miller Thunderbolt 225Millermatic 130 XPLincoln HD 100 Forney C-5bt Arc welderPlasma Cutter Gianteach Cut40ACent Machinery Bandsaw Cent Machinery 16Speed Drill PressChicago Electric 130amp tig/90 ArcHobart 190 Mig spoolgun ready
Reply:definately looks dirty clean it and everything around it  leave most of the meat you already added and go over it the best thing to do now is melt your filler into you piece meaning when welding try to keep your rod under your tungsten after heating you piece up this will eliminate further contamination an hopefully seal.
Reply:Low heat and try to run small beads right over what you have done.   Did you use Mig wire for filler?Thats a pretty good job.  Pressure goes up to 300 in a R134a system.DavidReal world weldin.  When I grow up I want to be a tig weldor.
Reply:Thanks for the tips guys.  I will carefully go over it again.  It was for the most part successful the first time except for the pinhole leak.  I know where the leak is so I will go over that part and hopefully it'll be drum tight this tim.I used a TIG the first time too and it was with AL filler.  Never new there were diff grades of AL filler.  I ran around today and couldn't find the good stuff.  Will just take my time and take another run at it.
Reply:If it doesn't work, I'll resort to ordering some of this stuff next week.http://www.muggyweld.com/super5.html
Reply:Originally Posted by TeCKis300If it doesn't work, I'll resort to ordering some of this stuff next week.http://www.muggyweld.com/super5.html
Reply:Originally Posted by TeCKis300Thanks for the tips guys.  I will carefully go over it again.  It was for the most part successful the first time except for the pinhole leak.  I know where the leak is so I will go over that part and hopefully it'll be drum tight this tim.I used a TIG the first time too and it was with AL filler.  Never new there were diff grades of AL filler.  I ran around today and couldn't find the good stuff.  Will just take my time and take another run at it.
Reply:Just remember that you can put a LOT of pressure in a small line like that.  All you need to do is seal it up.  Don't worry about penetration or anything, or you could restrict the flow.I've put 1800psi into a piece of 3/8" tubing.  The wall thickness was .035".  This was done on a regular basis, and the only time we had problems was when the tube seam failed.Just mark where the pinhole was and close it up.
Reply:No luck re-welding.The problem I have now I believe is that the base material is contaminated with A/C oils.  Every time I go in to weld, the finish comes out porous and contaminated.  It seems while I fix one leak, another one appears.I've tried all the techniques of cleaning and pulling away heat gradually.  I may need to take the recommendation above and carefully grind away some metal and take another go.I believe I'll need to braze some sealant on.  Unfortunately, A/C specific brazes and solders are not readily available.There's the muggyweld stuff, and braze perfect.  Somehow, I think all those operations are tied together and seem like a scam.  Weird.I picked up some silver solder today and will try to braze it.Last edited by TeCKis300; 01-09-2008 at 04:34 PM.
Reply:Originally Posted by TeCKis300No luck re-welding.The problem I have now I believe is that the base material is contaminated with A/C oils.  Every time I go in to weld, the finish comes out porous and contaminated.  It seems while I fix one leak, another one appears.I've tried all the techniques of cleaning and pulling away heat gradually.  I may need to take the recommendation above and carefully grind away some metal and take another go.I believe I'll need to braze some sealant on.  Unfortunately, A/C specific brazes and solders are not readily available.There's the muggyweld stuff, and braze perfect.  Somehow, I think all those operations are tied together and seem like a scam.  Weird.I picked up some silver solder today and will try to braze it.
Reply:David,I appreciate the feedback and your posts are right on.  I am just trying to find the skill to be worthy of the fix and at the moment, I don't have it.The repair area is also at an awkward angle and I'm having a hard time focusing on it. I will regrind down the aluminum and give it another shot.
Reply:Originally Posted by TeCKis300David,I appreciate the feedback and your posts are right on.  I am just trying to find the skill to be worthy of the fix and at the moment, I don't have it.The repair area is also at an awkward angle and I'm having a hard time focusing on it. I will regrind down the aluminum and give it another shot.
Reply:No offense taken.  I am just being realistic about my abilities and looking for options.I tried the silver solder option as I had nothing to lose and was about to grind down the splooge.  Cleaned it up real good with a brush and acetone...Much to my surprise, it flowed?!  I don't think I have a superficial joint because it looks like it flowed and bonded?I tested the line once again and it's held vacuum through the night.  I might just leave it like this and charge her up.  I can always come back to it again if it doesn't proove to work since I have everything at my disposal in the garage.Wish me luck.Dave, what's your opinion on A/C sealers?  I'm not about to use it and compromise my Lexus's A/C system.  Just want to know your thoughts.  I can't imagine it good for more than a 1 time temporary fix.
Reply:Originally Posted by TeCKis300No offense taken.  I am just being realistic about my abilities and looking for options.I tried the silver solder option as I had nothing to lose and was about to grind down the splooge.  Cleaned it up real good with a brush and acetone...Much to my surprise, it flowed?!  I don't think I have a superficial joint because it looks like it flowed and bonded?I tested the line once again and it's held vacuum through the night.  I might just leave it like this and charge her up.  I can always come back to it again if it doesn't proove to work since I have everything at my disposal in the garage.Wish me luck.Dave, what's your opinion on A/C sealers?  I'm not about to use it and compromise my Lexus's A/C system.  Just want to know your thoughts.  I can't imagine it good for more than a 1 time temporary fix.
Reply:Allways pressure test with Nitrogen!Not shop air.... compressor oil in the shop air is a no no an Any AC system.Miller Thunderbolt 225Millermatic 130 XPLincoln HD 100 Forney C-5bt Arc welderPlasma Cutter Gianteach Cut40ACent Machinery Bandsaw Cent Machinery 16Speed Drill PressChicago Electric 130amp tig/90 ArcHobart 190 Mig spoolgun ready
Reply:Originally Posted by STwelderAllways pressure test with Nitrogen!Not shop air.... compressor oil in the shop air is a no no an Any AC system.
Reply:Originally Posted by TeCKis300Snip...Dave, what's your opinion on A/C sealers?  I'm not about to use it and compromise my Lexus's A/C system.  Just want to know your thoughts.  I can't imagine it good for more than a 1 time temporary fix.
Reply:AC sealer is snake oil. After doing thousands of automotove AC jobs at my past job, I would never touch this junk. If I knew it was used in a system I was servicing, the customer would pay dearly...especially if they goobered up my new Robinair machine or a 50# bottle of R12 that was worth over a grand at the time.We have a local guy (ancient, old as dirt guy) that did some line repairs for us. He would weld new fittings and such when needed for street rods and other custom installations. He did it with Oxy/Acet and they looked NASTY when done. SOB's never leaked once though.