Cable with overtravel Spring Figure 47-9 shows a system with an upstroke pawl advance. The left brake has left-hand threads, and the right brake has right-hand threads. The lever (pawl) is installed on a web pin with an additional pawl return mousetrap spring. The cable is hooked to the lever (pawl) by means of an overtravel spring installed in the cable hook. The overtravel spring dampens movements and prevents unnecessary adjust- should sudden hard braking cause excessive drum deflection and shoe movement.