There are two flex lines on the front,)axle)and one rubber line on the rear,usually located above the differential. These lines deteriorate,(from brake fluid,combined with rust from the steel lines), from the inside-out,like the steel lines,but they collapse,sometimes completely restricting flow. There are rubber lines that attach to the hydrovac, for vacuum assist.I'm replacing all of my lines,brake and vacuum,(rubber and steel). Most are as old as the truck,and need replaced,anyway. There is a vacuum check-valve,located on the vacuum manifold. it,(manifold),is attached to the firewall. If this becomes inoperative,it will eliminate vacuum to the hydrovac,and 2-speed,(if so equipped). We think that's part of the problem,with Billy W's '59 Viking 60,bus. We'll find out Tuesday!
Last edited by wetwilly5757; 05/05/2014 3:53 AM.
