Gates 25309 Radiator Coolant Hose - Lower, Lower - Engine To Pipe or Upper

Flexible coolant hose for OE-style routing

The Gates Vulco-Flex II radiator coolant hose is built for applications that need a flexible replacement with a precise sealing surface. It bends in almost any direction to follow the angles and planes of many original coolant hose layouts, making it a practical choice for service on older Ford, Chevrolet, GMC, and other listed vehicles.

Gates Flexible Coolant Hose (Standard), part number 25309, is designed for upper and lower radiator hose applications where a formed hose is not the right match. Its EPDM and steel construction supports durability, while the improved sealing surface helps reduce leak risk at the connection points.

Key features

• Flexible radiator coolant hose for upper and lower cooling system routing
• EPDM and steel construction for strength and heat resistance
• 1.25 in. end 1 inside diameter, 1.5 in. end 2 inside diameter
• 26 in. centerline length for service on longer hose runs
• Non-molded design for routing around tight engine bay layouts
• Improved sealing surface for better leak resistance at the hose ends

Product details

This Gates coolant hose is made for direct replacement of many OE-style radiator hose applications where a flexible hose is preferred over a molded shape. The design helps replicate the required bends without forcing the hose into a fixed form, which is useful on vehicles such as the Ford Mustang, Chevrolet S10, and Lincoln Mark VII listed in the fitment data. Part number 25309 is also cross-referenced as Gates 31625 for the same application.

Compatible With 1983-1987 Ford Mustang, upper; 1989-1993 Ford Mustang, upper; 1986-1990 Chevrolet S10, upper; 1987-1992 Lincoln Mark VII, upper; and other listed upper and lower radiator hose applications across the 1980-1993 model years.

Common repair uses

• Replacing a cracked or hardened radiator coolant hose
• Restoring coolant flow after hose collapse or deformation
• Addressing seepage at hose connection points
• Replacing an OE hose with an expensive or hard-to-find formed hose
• Servicing upper or lower cooling system hose routing on listed vehicles

Installation notes and tips

• Verify end diameters and centerline length before installation: 1.25 in. to 1.5 in. with a 26 in. centerline length.
• Confirm whether the vehicle uses an upper or lower hose position, since fitment varies by application.
• Inspect hose necks, clamps, and mating surfaces for corrosion or damage before installing the new hose.
• Drain coolant as needed and refill the system according to the vehicle service procedure after installation.
• Check routing clearance so the hose does not contact belts, pulleys, or hot exhaust components.

Quality assurance

Gates manufactures this Vulco-Flex II hose as a durable replacement for demanding cooling system service. The improved sealing surface and flexible construction are intended to support reliable fitment on the listed applications, including Ford Mustang, Chevrolet S10, and Lincoln Mark VII cooling system repairs.