Been fabricating my A/C lines and found no off-the-shelf ones of the required length. So I got a tubing expander and am making braze-on tube couplers.

It took me 4 "practice" tries with extra tubing to get good joints, but I still ruined 1-1/2 tubes to make two good ones.

I found that the "special for aluminum" flux did'nt help at all, in fact, it made it harder. I learned that the key is to make certain the surfaces to be joined are super clean. I used electrical contact cleaner, after fully abrading the surfaces with a S. Steel brush, (not carbon steel). The hard aluminum/silver solder flows fine, but the parts have to be very hot, just to the point where the heated surfaces start to look shiney.

Now I need to make the big return line, but that's next week because I need to borrow a tubing bender capable of bending 5/8" OD soft aluminum tube.

I'm mounting the compressor where the air pump used to be. To do this I hand fabricated adaptor mounts for the Sanden compressor out of 3/16" aluminum plate that mate-up to the existing air pump engine block bracket.

It won't look like a fully professional job, but I don't think it will look that bad either. Pics to come when the under-hood work is complete.

I usually have trouble soldering aluminum too. Usually the soot from the flame is the problem, but since the parts are very small, I can reclean, and try the 100W soldering ion.

fwiw