Dayco 71305 Radiator Coolant Hose - Upper

Curved radiator hose for OE-style cooling service

Dayco 71305 is a curved radiator coolant hose built for upper radiator connections that need a formed EPDM hose with a 1 1/4 in. inside diameter at both ends. It is a black, single I.D. hose made to SAE J20R4 Class D-1 and SAE J1684 Type EC specifications for cooling-system service.

Use Dayco 71305 when replacing a worn upper radiator hose on select Mazda Millenia, Mitsubishi Expo LRV, Dodge Colt, Chevrolet Cavalier, Buick Skyhawk, and Oldsmobile Firenza applications. The Dayco Curved Radiator Hose line is focused on formed hose routing that follows the vehicle’s cooling path without unnecessary strain at the connection points.

Key features

• EPDM construction for radiator coolant service
• Curved, single I.D. hose design
• 1 1/4 in. inside diameter at both ends
• Black finish for a clean OE-style appearance
• Built to SAE J20R4 Class D-1 and SAE J1684 Type EC standards
• Upper radiator hose position
• Dayco part number 71305

Detailed description

Dayco 71305 is a formed radiator coolant hose intended for upper hose routing where a curved profile is required. Its EPDM rubber construction is selected for cooling-system use, while the 14 1/4 in. trunk height and matched 1 1/4 in. end diameters support proper routing and connection at the radiator and engine-side fittings. This part cross-references Gates (e.g., 21592, 22326) for the same application.

Fitment includes 1995-2002 Mazda Millenia, upper; 1992-1994 Mitsubishi Expo LRV, upper; 1992 Dodge Colt, upper; 1987-1991 Chevrolet Cavalier, upper; 1987-1989 Buick Skyhawk, upper; and 1988-1987 Oldsmobile Firenza, upper. For 1987 Oldsmobile Firenza, the listing includes upper hose applications for vehicles with air conditioning and for vehicles without air conditioning.

What this hose helps address

• Cracked or split upper radiator hose material
• Coolant leaks at the hose connection points
• Collapsed or softened hose sections from age and heat
• Poor hose routing caused by a misshaped replacement hose
• Cooling-system service on vehicles needing a curved upper hose

Installation notes and tips

Confirm the end inside diameter, hose routing, and upper-position fitment before installation. Inspect the radiator neck and engine-side tube for corrosion, sharp edges, or residue that can affect sealing. Replace clamps as needed and verify that the hose follows the original path without twisting or kinking after installation.

Quality assurance

Dayco 71305 is manufactured to SAE J20R4 Class D-1 and SAE J1684 Type EC specifications for radiator hose service. The EPDM construction and formed profile support consistent fitment on the listed applications, including Mazda Millenia, Mitsubishi Expo LRV, Chevrolet Cavalier, Buick Skyhawk, Oldsmobile Firenza, and Dodge Colt upper radiator hose locations.