---tab Description--- Upper Coolant Tube for 2017-2025 L5P 6.6L Duramax Chevy/GMC 2500HD/3500HD Coolant Pipe Kit SPELAB The SPELAB Upper Coolant Tube is a premium upgrade designed to replace the factory plastic and rubber upper radiator hose on your 2017–2025 L5P Duramax. Built from high-grade 6061 aluminum with heavy-duty multi-ply silicone couplers, this system eliminates the failure-prone OEM parts and delivers long-lasting durability, clean aesthetics, and improved cooling reliability under heavy load or tuned conditions. Upper Coolant Tube Key Features 6061-T6 Aluminum ConstructionMandrel-bent aluminum tubing resists heat, pressure, and aging far better than OEM rubber. CNC-Machined Thermostat Housing & Radiator AdapterEnsures a perfect leak-free connection and long-term durability. Powder-Coated Finish (Multiple Colors Available)Durable, corrosion-resistant coating adds a premium look to your engine bay. Direct Bolt-On InstallationNo cutting or fabrication required — designed as a direct replacement for your factory upper coolant tube assembly. L5P Upper Coolant Tube Specification Material 6061-T6 Aluminum Construction & Silicone Weight 1.5 kg Installation Engine block or thermostat housing to the upper radiator section What's in the BOX? 1 × Aluminum upper coolant tube 2 × Silicone couplers 4 × Stainless steel T-bolt clamps ---tab Fitment & FAQ--- FITMENT 2017-2025 L5P 6.6L Duramax Diesel GMC Sierra 2500 HD 2017-2025 L5P 6.6L Duramax Diesel GMC Sierra 3500 HD 2017-2025 L5P 6.6L Duramax Diesel Chevrolet Silverado 2500 HD 2017-2025 L5P 6.6L Duramax Diesel Chevrolet Silverado 3500 HD FAQ Why should I upgrade my L5P Duramax to an aluminum upper coolant tube? The factory upper radiator hose uses plastic and rubber components that are prone to failure under heat and pressure. SPELAB's 6061-T6 aluminum tube provides a long-lasting, leak-free solution that resists aging and improves overall cooling reliability. Is this coolant pipe kit compatible with both Sierra and Silverado HD trucks? Yes, this kit is specifically designed for 2017-2025 GMC Sierra 2500/3500 HD and Chevrolet Silverado 2500/3500 HD trucks equipped with the 6.6L L5P Duramax Diesel engine. Does the installation of the SPELAB upper coolant tube require any modifications? No, this is a direct bolt-on replacement for your factory upper coolant tube assembly. It requires no cutting or custom fabrication during installation. What material are the couplers and clamps made of in this kit? The kit features heavy-duty multi-ply silicone couplers and four stainless steel T-bolt clamps to ensure a secure, leak-free connection between the aluminum tube and the engine/radiator adapter. Can this upgrade help reduce engine operating temperatures? Yes. By replacing aging OEM rubber parts with mandrel-bent 6061 aluminum tubing, this modification helps improve cooling reliability and can reduce engine operating temperatures by approximately 20–25°F under heavy load. ---tab Blog & Video--- Video...