Karl Townsend wrote:
The AC broke in my John Deere. AC is needed a bit more in a tractor
cause you get A LOT of heat off the machine, the cab is all glass, and
one little window to open. Easily 20 degrees over outside.

My neighbor is an HVAC tech. We found a hole in the condenser caused
the failure. First braze attempt still had a small leak. The second
attempt, the braze slumped into the line and party blocked it. Now I'm
FUBAR.

Somehow, I need to cut this braze out and weld a patch over it. Or
pull a 180 U off of one end and bypass this run. It is the first top
run on the condenser. Anyone successfully done either operation?

I looked for generic replacements. John Deere isn't listed. No joy
trying to find one based on length and width. For those that don't
know, John Deere selected their tractor color because of the amount of
green you need to buy a part. Anybody know of a place that will supply
a condenser that fits within a certain height and width? I do know a
machinist that can build a bracket.

Karl


The braze you used probably had too high a melting point. You should
use a phoscop or similar brazing rod that has a lower melting point than
copper. Silver solder would work too. There are also epoxy compounds
that are used but I have no experience with them. I do only industrial
chillers and coolers on machine tools. I fixed a leak in a condenser
the other week after a refrigeration guy couldn't find it.
When you braze the leak you should purge the system with dry nitrogen to
get all the freon gas out of the system or you will make hydrofloric
acid when it breaks down from the heat of the brazing. The acid will
cause premature failure of the system.
Most guys don't take the trouble to do the job right. It also gets them
more work in the future.

John