Originally Posted by ggray
Do you mean you braze the copper tube in the banjo fitting?
Solder is only is the way to go. Brazing copper tubing is never a good idea as the brazed section becomes annealed and thermal expansion will cause the non-annealed copper to push into the annealed section, which will cause it to leak. The firm I was with in Colorado tested this in 1994 with 1" copper.
Brazed tubing will fail rather quickly, months, not years, if exposed to vibration and temperature changes. In a building with 10,000 brazed copper joints (LUXOR vegas) it can be annoying. Luckily our spec, called for soldering. Contractor brazed, which was and is common. But it has issues.
I soldered my Yanmar's replacement copper tubing (3/32" if I recall) in 2013 and it's still going strong with well over 500 hours on it.