Gates 21504 Radiator Coolant Hose - Lower or Upper

Gates 21504 Molded Coolant Hose

The Gates 21504 molded coolant hose is built for radiator cooling system service with OEM-quality specifications and a formed shape that matches the original routing. It is made from EPDM for coolant resistance and is shaped for upper, lower, bypass, heater, and other coolant applications where a molded hose is required.

Compatible with select Toyota Corolla lower hose and Ford Thunderbird upper hose applications, this molded coolant hose helps restore proper coolant flow and factory-style fitment. Gates 21504 is part of the Gates Molded Coolant Hose line, which covers a wide range of replacement needs for radiator hose service.

Key Features

• Brand: Gates Molded Coolant Hose
• Part number: 21504
• Part type: radiator coolant hose
• Material: EPDM
• Molded construction for formed routing
• End 1 inside diameter: 1.18 in. (30 mm)
• End 2 inside diameter: 1.18 in. (30 mm)
• Centerline length: 16.1 in. (409 mm)
• Contains spring: No
• Branch quantity: 0
• Number of quick connect fittings: 0

Product Details

The Gates Molded Coolant Hose line is engineered for direct replacement use in cooling system repairs where a shaped hose is needed to match the vehicle’s original hose path. Gates 21504 is a molded EPDM radiator coolant hose with equal 30 mm ends and a 409 mm centerline length, making it suitable for specific upper and lower coolant routing applications. This part number is referenced for 1984-1987 Toyota Corolla lower hose service and 1982 Ford Thunderbird upper hose service.

This part cross-references Dayco 70931 for the same application.

Common Cooling System Issues It Can Address

• Cracked or split radiator hose material
• Coolant leaks at a worn molded hose section
• Collapsed or misshaped hose routing
• Restricted coolant flow from deteriorated hose walls
• Incorrect fitment after a previous hose replacement

Installation Notes and Tips

Verify hose routing, end diameters, and centerline length before installation. Confirm whether the vehicle uses an upper or lower hose position, then compare the original hose shape to Gates 21504 before removal. Inspect adjoining clamps, necks, and coolant passages for wear or corrosion so the new hose seals correctly.

For fitment reference, this hose fits 1984-1987 Toyota Corolla, lower, and fits 1982 Ford Thunderbird, upper. Confirm the original hose profile and connection points against the vehicle before service.

Quality Assurance

Gates manufactures this molded coolant hose to OEM-quality specifications for radiator hose replacement service. The EPDM construction and molded form support consistent fitment in cooling system applications, and the Gates 21504 part number is backed by the brand’s established cooling hose product line.