Dayco 71779 Radiator Coolant Hose - Upper

Dayco Curved Radiator Hose 71779

The Dayco 71779 curved radiator hose is a direct-fit coolant hose for select Buick, Oldsmobile, and Pontiac applications. Built from EPDM rubber and formed as a single I.D. hose, it provides the correct upper hose routing for vehicles that need a 1 9/32-inch inside diameter at both ends.

This Dayco Curved Radiator Hose line focuses on OE-style cooling system replacement parts with the shape and dimensions needed for proper coolant flow and routing. For shoppers searching for a radiator coolant hose for a 1996-1999 Buick LeSabre or a 1995-1999 Pontiac Bonneville, part number 71779 is a fitment-specific option.

Key Features

• EPDM construction for cooling system service
• Black finish
• Single I.D. hose design
• 1 9/32-inch inside diameter at both ends
• Upper curved radiator hose application
• Built to SAE J20R4 Class D-1 and SAE J1684 Type EC specifications
• Dayco part number 71779

Product Details

Dayco 71779 is a curved radiator hose made for upper radiator hose routing in select GM vehicles. The EPDM material is commonly used in coolant hose construction for its resistance to heat and coolant exposure, while the curved shape helps match the factory hose path. This radiator coolant hose is listed for 1996-1999 Buick LeSabre, 1995-1999 Oldsmobile 88, 1996-1999 Oldsmobile LSS, 1995-1999 Pontiac Bonneville, 1997-1998 Oldsmobile Regency, 1995-1996 Buick Park Avenue, and 1995-1996 Oldsmobile 98.

This part cross-references Gates 21959 and NAPA 8649 for the same application. If you are replacing a leaking upper radiator hose on a Buick LeSabre, Oldsmobile 88, or Pontiac Bonneville, 71779 provides the correct fitment profile for those listed vehicles.

Common Problems This Hose Can Address

• Coolant leaks from a cracked or aged upper radiator hose
• Softening, swelling, or collapse of the original hose
• Improper hose routing after a cooling system repair
• Loss of coolant from a damaged hose connection point
• Overheating caused by restricted coolant circulation through a failing hose

Installation Notes and Tips

Verify the vehicle year, make, model, and upper hose position before ordering. Compare the hose shape and both end inside diameters to the original part before installation. Inspect hose clamps, radiator necks, and thermostat housing connections for wear or corrosion, and replace any damaged sealing surfaces before installing the new hose.

After installation, refill the cooling system with the correct coolant mixture and check for leaks with the engine at operating temperature. Confirm that the hose follows the factory routing without kinks or tension.

Quality Assurance

Dayco manufactures this radiator hose to SAE J20R4 Class D-1 and SAE J1684 Type EC specifications, supporting consistent material and dimensional requirements for cooling system service.