I needed straight line to run new brake lines on a school bus at work. We had a piece of channel iron 4" wide and a handful of idler pulley bearings. I laid out 4 bearings on one side, 3 on the other spaced between the four so the tubing snakes its way through them. On each end we had one vertical to hold the tubing down. I used 3/8" nuts, bolts, and washers to give me room to adjust each bearing, the holes in the bearings were 1/2" or slightly bigger. One guy feed the line in while unrolling the coil, another pulled it through. A couple of passes through and we had a straight 50 foot piece of 1/4" brake line ready to use. It works like the hand held versions only ours was vise mounted and cost nothing to build with what we had laying around. The more bearings or rollers you have, the better it works.
Last edited by Joe H; 11/11/2025 2:29 PM.
