Rubber is out, and silicone is in for your Subaru radiator hoses! A leaking radiator hose can lead to serious engine damage if not quickly identified. Upgrade your cooling system with this Silicone Radiator Hose Kit for the perfect combination of performance and durability. Radiator hoses are manufactured with high-grade silicone and four layers of heat-resistant embedded fibers to provide increased pressure and temperature tolerance.