Gates 18866 HVAC Heater Hose - Heater To Pipe-1

Gates Molded Heater Hose 18866 Overview

The Gates 18866 molded heater hose is an OEM-style coolant hose built for tight engine compartments where a straight hose will not route correctly. It is formed to match the factory shape and is suitable for coolant, water, and air service, with marine application approval.

Compatible with select 1989-1994 Mitsubishi and Plymouth applications, this molded heater hose supports clean routing in heater-to-pipe connections. The Gates Molded Heater Hose line focuses on factory-shaped replacement hoses for vehicles with compact underhood packaging.

Key Features

• Brand: Gates
• Brand line: Molded Heater Hose
• Part number: 18866
• EPDM construction for coolant-system service
• Factory-molded shape for tighter engine compartments
• End 1 inside diameter: 0.62 in. (16 mm)
• End 2 inside diameter: 0.62 in. (16 mm)
• Centerline length: 16.2 in. (411 mm)
• Molded design with no branch quantity
• Approved for marine applications

Detailed Description

Gates 18866 is a molded HVAC heater hose made from EPDM and shaped to follow the original routing used in compact engine bays. The 0.62-inch inside diameter at both ends and 16.2-inch centerline length make it a direct-style replacement for heater-to-pipe routing where a formed hose is required. This part cross-references Continental 63257 for the same application.

Fits 1989-1992 Mitsubishi Galant, Heater To Pipe-1. Fits 1990-1994 Mitsubishi Eclipse, Heater To Pipe-1. Fits 1990-1994 Plymouth Laser, Heater To Pipe-1. Use Gates 18866 when you need an OE-style molded hose for these heater circuit layouts.

Common Problems It Can Address

• Cracked or hardened heater hose material
• Improper hose routing in tight engine compartments
• Coolant seepage at a worn heater hose section
• Collapsed or misshaped hose bends
• Replacement needs for heater-to-pipe connections on listed vehicles

Installation Notes and Tips

Verify hose routing against the original part before installation, especially on Mitsubishi Eclipse, Plymouth Laser, and Mitsubishi Galant applications. Confirm both end diameters and the molded shape match the vehicle’s heater-to-pipe layout. Inspect adjoining pipes and clamps for wear or corrosion before installing the new hose.

Quality Assurance

Gates manufactures this molded heater hose as an OE-style replacement built for factory fit and routing. The EPDM construction and molded form support consistent performance in coolant, water, air, and approved marine applications.