Product Details: Prevent water vapors and contaminants from leading to brake malfunctions, with the Bendix AD-9si® Oil Coalescing Air Dryer that ensures you're Ready for the Road Ahead®. This air dryer effectively removes moisture from compressed air through an internal desiccant to prevent system damage and ensure optimal performance. Once installed, the device can dramatically extend the lifetime of an existing brake system. To see if your air dryer needs replacing, check for signs such as leaking air, blocked purge valves, or poor-performing condensers that can't receive built pressure. FleetPride is your First Click in Heavy Duty®.