Gates 51501 Radiator Coolant Hose - Lower or Lower Right

Gates Molded Coolant Hose for Audi Cooling Repair

The Gates 51501 molded coolant hose is built for specific Audi cooling system applications that require an OE-style formed hose with integrated connection points. It is a direct-fit radiator coolant hose for select Audi A4 Quattro, A5, A5 Quattro, A4, Q5, S4, and S5 models with lower or lower right routing.

Gates Molded Coolant Hose products are application-specific assemblies that mirror OEM-style layouts, including molded shapes and integrated components where required. This helps maintain proper coolant flow path and connection integrity in vehicles that use a modular hose design.

• Material: EPDM, plastic, and steel construction
• Molded hose design for exact routing
• 1.5 in. / 38 mm inside diameter at both ends
• 19 in. / 483 mm centerline length
• Includes one female quick connect fitting and a bleeder valve
• No spring included
• Modular hose design for OE-style cooling system service

Detailed Product Overview

This Gates 51501 radiator coolant hose is engineered for lower cooling system routing on select Audi platforms, including 2008-2011 Audi A5, 2008-2011 Audi A5 Quattro, 2009-2011 Audi A4 Quattro, 2009-2012 Audi Q5, 2010-2015 Audi A4, 2010-2015 Audi S5, 2016 Audi S4, 2016 Audi S5, and 2017 Audi S5. It also cross-references Genuine 8K0121055B for the same application. If you are replacing a worn Audi S4 lower right coolant hose or a lower radiator coolant hose on an Audi S5, part number 51501 provides the correct molded layout and integrated connection style.

Common Problems This Hose Can Address

• Coolant leaks from cracked or aged hose material
• Improper fit from a straight universal hose in a formed routing location
• Connection issues at the quick-connect interface
• Air trapped in the cooling circuit where a bleeder valve is required
• Heat-related deterioration in the lower radiator hose path

Installation Notes and Tips

Confirm the vehicle’s engine and hose routing before installation, especially on Audi A4 Quattro, A5 Quattro, Q5, S4, and S5 applications where lower and lower-right positions are listed. Inspect mating connectors, clamps, and adjacent plastic fittings for wear before installing the new hose. Verify the bleeder valve orientation and ensure the quick connector seats fully to prevent coolant loss.

Quality Assurance

Gates is a recognized automotive aftermarket supplier with a focus on modular coolant hose assemblies that follow OE-style application requirements. The 51501 is built to match the specified fitment and integrated component layout for the listed Audi vehicles.