Dayco 72409 Radiator Coolant Hose - Lower or Lower - Passenger Side (Thermostat To Tee)

Curved Radiator Hose for Mazda 3 and Toyota Prius

Dayco 72409 is a curved radiator coolant hose built for specific lower cooling-system routes on select Mazda 3, Mazda 3 Sport, and Toyota Prius applications. Made from EPDM and finished in black, it follows the OE-style routing needed for thermostat-to-tee and lower radiator connections.

Key Features

• EPDM construction for coolant-system service
• Black finish for a clean OE-style appearance
• Single I.D. hose design
• End 1 inside diameter: 1 3/16 in.
• End 2 inside diameter: 1 3/16 in.
• End 1 outside diameter: 1 15/32 in.
• End 2 outside diameter: 1 15/32 in.
• Built to SAE J20R4 Class D-1 and SAE J1684 Type EC specifications
• Dayco 72409 curved radiator hose for direct-fit cooling-system service

Product Details

This Dayco curved radiator hose is engineered for lower coolant routing where a formed hose is required to maintain proper alignment and flow. It fits 2010-2013 Mazda 3, lower - passenger side (thermostat to tee); 2012-2013 Mazda 3 Sport, lower - passenger side (thermostat to tee); and 2004-2009 Toyota Prius, lower. This part cross-references ACDelco 20430S and Gates 22961 for the same application.

Dayco 72409 is a practical replacement for aging or damaged radiator hoses on Mazda 3 and Toyota Prius cooling systems. The curved profile helps match the factory hose path, while the EPDM material and SAE-based construction support consistent coolant transfer in the specified applications.

Common Problems This Hose Can Address

• Coolant leaks from a cracked or split lower radiator hose
• Softening, swelling, or deterioration from heat and age
• Improper hose routing after a previous repair
• Restricted coolant flow caused by a collapsed hose
• Loss of cooling-system integrity at the thermostat-to-tee connection

Installation Notes and Tips

Verify hose routing, end diameters, and vehicle application before installation. Inspect adjoining clamps, tees, thermostat housing connections, and radiator necks for wear or corrosion before transferring the new hose into service. Confirm the hose is seated fully and routed without twists or contact points that could cause abrasion.

Quality Assurance

Dayco 72409 is manufactured to meet SAE J20R4 Class D-1 and SAE J1684 Type EC requirements for the listed applications. The EPDM construction and formed shape support OE-style fitment for the specified Mazda 3, Mazda 3 Sport, and Toyota Prius cooling-system layouts.