Gates 21774 Radiator Coolant Hose

Gates 21774 Molded Coolant Hose Overview

The Gates 21774 molded coolant hose is an OE-style radiator coolant hose built for specific cooling system routing on select Chevrolet and GMC trucks and vans. Made from EPDM, it is shaped to match the original hose path and connection sizes for a direct replacement on listed applications.

Gates Molded Coolant Hose products are engineered for upper, lower, bypass, heater, and other coolant routing needs, giving technicians a replacement option that follows OEM-quality specifications. The 21774 hose is part of Gates’ molded coolant hose line for radiator hose replacement on vehicles such as the Chevrolet S10 and GMC Sonoma.

Key Features

• Brand: Gates Molded Coolant Hose
• Part number: 21774
• EPDM construction for coolant system service
• Molded hose shape for factory-style routing
• End 1 inside diameter: 15 mm (.61 in)
• End 2 inside diameter: 17 mm (.68 in)
• Centerline length: 465 mm (18.3 in)
• No spring included
• No quick connect fittings
• Compatible with select Chevrolet and GMC cooling system applications

Detailed Description

Gates 21774 is a molded radiator coolant hose designed to replace the original hose on specific GM applications with the correct formed shape and connection dimensions. The EPDM material is commonly used in cooling system service for its resistance to heat and coolant exposure, while the molded profile helps maintain proper hose routing in tight engine compartments. This part cross-references Continental 63039 and Dayco 71390 for the same application.

Fits 1987-1993 Chevrolet S10, N/A; fits 1991-1993 GMC Sonoma, N/A; fits 1987-1990 Chevrolet Astro, N/A; fits 1987-1990 GMC S15, N/A; fits 1987-1990 GMC Safari, N/A; fits 1987-1988 Chevrolet S10 Blazer, N/A; fits 1987-1988 GMC S15 Jimmy, N/A. Use Gates 21774 when replacing a molded coolant hose on these Chevrolet S10 and GMC Sonoma applications.

Common Cooling System Issues

• Cracked or split radiator hose material
• Coolant leaks at the hose body or ends
• Collapsed or misshaped hose routing
• Improper fit from a straight universal hose
• Cooling system service on aging Chevrolet and GMC vehicles

Installation Notes and Tips

Verify end diameters and centerline length against the removed hose before installation. Inspect hose clamps, mating necks, and nearby cooling components for wear or corrosion, and replace damaged parts as needed. Confirm the hose follows the original routing without kinks or twist before refilling and bleeding the cooling system.

Quality Assurance

This Gates molded coolant hose is manufactured to OEM-quality specifications for listed applications and is part of Gates’ broad replacement hose line for radiator and coolant service.