Automotive Air Conditioning Information Forum

Hi, I leaned on one of my AC lines causing a very small leak at an all metal sodered joint (I think at the "drier" but not sure). If I pulled up on the line the freon stopped misting out so I strapped the line up and also used a strip of rubber and small "C" clamp and my AC has been fine for 6 months.
My question is since just strapping the line up stops the leak if I remove my clamp can a repair shop soder or weld the tiny crack without having to realsase the freon already in the system?
Thanks

No

billr wrote:No

Am I correct that temperature to the charged freon is the reason it can't be sodered?
Besides clamping are there any other low temp solutions for this aluminum joint like J B Weld etc.?

billr wrote:No

Am I correct that temperature to the charged freon is the reason it can't be sodered?
Besides clamping are there any other low temp solutions for this aluminum joint like J B Weld etc.?

There are two problems. First, pressure leaking through the area you are trying to fill blows any molten metal out of where you want it; and if that fluid blowing out isn't inert, like He, N, Ar, etc, then the joint area gets contaminated and no good joint is possible. I don't know if R134A is suitably "inert", but I doubt it.

Second problem is that those parts are probably aluminum. Aluminum can be soldered/brazed in the best of conditions, but I have never come across anybody that can join aluminum by anything but fusion welding. Aluminum must be very clean for welding, even atmospheric moisture in the surface "pores" must be baked out, so large parts have to be pre-heated in the 200-400F range because aluminum conducts heat away so quickly. You are talking about small parts, so they could probably be "pre-heated" and "baked out" during the welding process... except that the pesky R134 is going to be cooling, blowing, and contaminating even more than normal because of the welding heat.

Oops, I forgot to address the JB Weld question. Yes, many patch methods can be considered, but there is no sure-cure. Each of these patching situations is unique.

Thanks very much for the info.
One thing I didn't make clear was after leaning on the line (pushed it down) caused this tiny leak so small they simply lifting the line back up completely stopped the leak as far as sodering or whatever. My concern was what might happen inside the charged system because of heat blast.
I did figure out I should probably just leave well enough alone with my clamp.

You haven't shared what vehicle, year, and refrigerant type.

A year ago I developed a pinhole in the high side line (rubber part) of my 1998 Frontier; it had 225K on it and apparently the fan clutch was "iffy", and it was 119F that day in Phoenix. Anyway, that truck had "untouched" factory R134a system, I was able to buy a replacement line for about $60, and I simply replaced the line, pulled vacuum, and added 2 cans of R134a (did not change the drier as the system was never open to the atmosphere except for the physical R&R of the line. Yesterday it was "only" 115F here, middle vent temperature was 45F.

So investigate just getting a brand-new line.