Guys - Fixing to re-pipe the brakes it is a 40's Ford system - got most of it sorted except for the 2 unions for the rear cylinders - are they 7/16 UNF maybe ?
No, all threads on a 40 are 7/16-24 which is the standard thread for a 1/4" pipe fitting. Except for where the hoses screw into the FRONT wheel cylinders, which is 7/16-20 (UNF). The rear brake pipes screw directly into the rear cylinders.
