Product Overview
The Automann 135.S2840 is a high-performance automatic slack adjuster designed as a direct aftermarket replacement for the Haldex 40020211 and compatible OEM equivalents.
It features a 1-1/2″ × 28-spline input and 5.5″ arm length, engineered for heavy-duty truck and trailer air-brake systems with 16.5″ drums.
This self-setting adjuster automatically maintains proper brake-shoe clearance, ensuring consistent braking power, reduced wear, and DOT compliance. Built from corrosion-resistant, heat-treated steel, it provides the same functionality and reliability as OEM Haldex units—ideal for fleet service or new trailer builds.
