Dayco 71518 Engine Coolant Bypass Hose

Dayco Curved Radiator Hose for Ford and Mercury

The Dayco 71518 is a curved radiator hose built as an engine coolant bypass hose for select Ford and Mercury applications. Made from EPDM rubber and formed as a dual I.D. hose, it is shaped to match the cooling system routing used on specific Explorer, Mountaineer, Thunderbird, and Cougar models.

Key Features

• Dayco Curved Radiator Hose, part number 71518
• Engine coolant bypass hose for select Ford and Mercury vehicles
• EPDM construction with black finish for cooling-system use
• Dual I.D. hose design with 17/32 in. end 1 and 23/32 in. end 2 inside diameters
• Built to SAE J20R4 Class D-1 and SAE J1684 Type EC specifications
• No heat shield and no protective sleeve

Product Details

Dayco 71518 is a curved radiator hose designed for cooling-system routing where a dual inside diameter is required. The EPDM material is selected for coolant service, while the curved shape helps match the factory hose path on vehicles such as the Ford Explorer, Mercury Mountaineer, Ford Thunderbird, and Mercury Cougar. This part cross-references Motorcraft KM1935 and Gates 20662 for the same application.

Common Uses

• Replacing a cracked or softened coolant bypass hose
• Restoring proper coolant flow in the engine cooling circuit
• Addressing coolant seepage at hose connections
• Correcting a hose that no longer holds its formed shape
• Servicing a worn hose on a Ford Explorer or Mercury Mountaineer cooling system

Installation Notes

Verify the end diameters before installation: 17/32 in. on one end and 23/32 in. on the other. Confirm routing against the original hose path and inspect adjoining clamps, fittings, and coolant passages before refilling the system. This hose is listed for 1996-2001 Ford Explorer, 1997-2001 Mercury Mountaineer, 1991-1993 Ford Thunderbird, and 1991-1993 Mercury Cougar.

Quality Assurance

Dayco manufactures this hose to meet SAE J20R4 Class D-1 and SAE J1684 Type EC requirements for coolant-hose service. The part number is 71518.