Ensure your semi is Ready for the Road Ahead™ with advanced control of its air brakes, with the Bendix SR-1 Series 1/4-18" NPTF Die Cast Zinc Spring Brake Valve. To actuate or release the air brakes, this replacement valve supplies or releases air to engage the braking mechanisms. Fashioned for use with dual circuit air brake systems that require responsive pressure control. FleetPride is your First Click in Heavy Duty®.