I installed new brake lines on my 54 3100 but couldn't stop the leak at the T fitting at the right side crossmember regardless how tight I made it. Took it back off and inspected it to find one of the small connections had lost the cone that mates with the brake line flare. Durn.
I found the pass-thru hole was a 3/32 drill. I drilled some copper sheet and trimmed it. Pushed the drill bit through the fitting, using it for a guide pin and slid the copper washer I made over the bit and into the fitting. Got under the truck and slid the brake line over the drill, started the threads and tightened until I just could remove the drill. Installed the other lines, tightened everything up and Shebang! No more leaks...
Thought this may help someone else save another T fitting. They are hard to find. FS had one for 28 bucks plus tax and shipping. Jethro.

~~ Jethro
1954 3100
Back to Life
In the Dity Gallery
1951 3100 (gone) / 1956 4400 (still in the neighborhood) / 1957 6400 with dump body (retired) / 1959 3100 panel (in the woods junked) / 1978 Custom Deluxe K10 / 1993 S-10 4.3 / 2004 Chevy Crew Cab / 1945 John Deere H / 1952 John Deere B / 1966 John Deere 2510 / 1967 John Deere 1020